America/Thunder_Bay

Time zone identifier: America/Thunder_Bay

Current civil offset: -05:00 (EST)

Current DST state: Observing Standard Time

First standard time adoption: Adopted on 1895-01-01

Local Mean Time (LMT): -05:17:32 based on geographic meridian

Total recorded transitions: 233 transitions across 3 distinct offsets

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Historical Offset Step Chart (1880 to Present)

-7:00 -6:00 -5:00 -4:00 -3:00 1880 1900 1920 1940 1960 1980 2000 2020

Text summary: America/Thunder_Bay shifted between 3 distinct offsets from 1895-01-01 through the modern era.

Complete Transition History (233 Transitions)

UTC Instant Local Wall Time Shift Abbreviation DST Effect
1895-01-01T05:17:32Z 1895-01-01 00:17:32 -05:17:32 → -05:00 EST No gap
1918-04-14T07:00:00Z 1918-04-14 03:00:00 -05:00 → -04:00 EDT Yes gap
1918-10-27T06:00:00Z 1918-10-27 01:00:00 -04:00 → -05:00 EST No overlap
1919-03-31T04:30:00Z 1919-03-31 00:30:00 -05:00 → -04:00 EDT Yes gap
1919-10-26T04:00:00Z 1919-10-25 23:00:00 -04:00 → -05:00 EST No overlap
1920-05-02T07:00:00Z 1920-05-02 03:00:00 -05:00 → -04:00 EDT Yes gap
1920-09-26T04:00:00Z 1920-09-25 23:00:00 -04:00 → -05:00 EST No overlap
1921-05-15T07:00:00Z 1921-05-15 03:00:00 -05:00 → -04:00 EDT Yes gap
1921-09-15T06:00:00Z 1921-09-15 01:00:00 -04:00 → -05:00 EST No overlap
1922-05-14T07:00:00Z 1922-05-14 03:00:00 -05:00 → -04:00 EDT Yes gap
1922-09-17T06:00:00Z 1922-09-17 01:00:00 -04:00 → -05:00 EST No overlap
1923-05-13T07:00:00Z 1923-05-13 03:00:00 -05:00 → -04:00 EDT Yes gap
1923-09-16T06:00:00Z 1923-09-16 01:00:00 -04:00 → -05:00 EST No overlap
1924-05-04T07:00:00Z 1924-05-04 03:00:00 -05:00 → -04:00 EDT Yes gap
1924-09-21T06:00:00Z 1924-09-21 01:00:00 -04:00 → -05:00 EST No overlap
1925-05-03T07:00:00Z 1925-05-03 03:00:00 -05:00 → -04:00 EDT Yes gap
1925-09-20T06:00:00Z 1925-09-20 01:00:00 -04:00 → -05:00 EST No overlap
1926-05-02T07:00:00Z 1926-05-02 03:00:00 -05:00 → -04:00 EDT Yes gap
1926-09-19T06:00:00Z 1926-09-19 01:00:00 -04:00 → -05:00 EST No overlap
1927-05-01T07:00:00Z 1927-05-01 03:00:00 -05:00 → -04:00 EDT Yes gap
1927-09-25T06:00:00Z 1927-09-25 01:00:00 -04:00 → -05:00 EST No overlap
1928-04-29T07:00:00Z 1928-04-29 03:00:00 -05:00 → -04:00 EDT Yes gap
1928-09-30T06:00:00Z 1928-09-30 01:00:00 -04:00 → -05:00 EST No overlap
1929-04-28T07:00:00Z 1929-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1929-09-29T06:00:00Z 1929-09-29 01:00:00 -04:00 → -05:00 EST No overlap
1930-04-27T07:00:00Z 1930-04-27 03:00:00 -05:00 → -04:00 EDT Yes gap
1930-09-28T06:00:00Z 1930-09-28 01:00:00 -04:00 → -05:00 EST No overlap
1931-04-26T07:00:00Z 1931-04-26 03:00:00 -05:00 → -04:00 EDT Yes gap
1931-09-27T06:00:00Z 1931-09-27 01:00:00 -04:00 → -05:00 EST No overlap
1932-05-01T07:00:00Z 1932-05-01 03:00:00 -05:00 → -04:00 EDT Yes gap
1932-09-25T06:00:00Z 1932-09-25 01:00:00 -04:00 → -05:00 EST No overlap
1933-04-30T07:00:00Z 1933-04-30 03:00:00 -05:00 → -04:00 EDT Yes gap
1933-10-01T06:00:00Z 1933-10-01 01:00:00 -04:00 → -05:00 EST No overlap
1934-04-29T07:00:00Z 1934-04-29 03:00:00 -05:00 → -04:00 EDT Yes gap
1934-09-30T06:00:00Z 1934-09-30 01:00:00 -04:00 → -05:00 EST No overlap
1935-04-28T07:00:00Z 1935-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1935-09-29T06:00:00Z 1935-09-29 01:00:00 -04:00 → -05:00 EST No overlap
1936-04-26T07:00:00Z 1936-04-26 03:00:00 -05:00 → -04:00 EDT Yes gap
1936-09-27T06:00:00Z 1936-09-27 01:00:00 -04:00 → -05:00 EST No overlap
1937-04-25T07:00:00Z 1937-04-25 03:00:00 -05:00 → -04:00 EDT Yes gap
1937-09-26T06:00:00Z 1937-09-26 01:00:00 -04:00 → -05:00 EST No overlap
1938-04-24T07:00:00Z 1938-04-24 03:00:00 -05:00 → -04:00 EDT Yes gap
1938-09-25T06:00:00Z 1938-09-25 01:00:00 -04:00 → -05:00 EST No overlap
1939-04-30T07:00:00Z 1939-04-30 03:00:00 -05:00 → -04:00 EDT Yes gap
1939-09-24T06:00:00Z 1939-09-24 01:00:00 -04:00 → -05:00 EST No overlap
1940-04-28T07:00:00Z 1940-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1942-02-09T07:00:00Z 1942-02-09 03:00:00 -04:00 → -04:00 EWT Yes offset-only
1945-08-14T23:00:00Z 1945-08-14 19:00:00 -04:00 → -04:00 EPT Yes offset-only
1945-09-30T06:00:00Z 1945-09-30 01:00:00 -04:00 → -05:00 EST No overlap
1946-04-28T07:00:00Z 1946-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1946-09-29T06:00:00Z 1946-09-29 01:00:00 -04:00 → -05:00 EST No overlap
1947-04-27T07:00:00Z 1947-04-27 03:00:00 -05:00 → -04:00 EDT Yes gap
1947-09-28T06:00:00Z 1947-09-28 01:00:00 -04:00 → -05:00 EST No overlap
1948-04-25T07:00:00Z 1948-04-25 03:00:00 -05:00 → -04:00 EDT Yes gap
1948-09-26T06:00:00Z 1948-09-26 01:00:00 -04:00 → -05:00 EST No overlap
1949-04-24T07:00:00Z 1949-04-24 03:00:00 -05:00 → -04:00 EDT Yes gap
1949-11-27T06:00:00Z 1949-11-27 01:00:00 -04:00 → -05:00 EST No overlap
1950-04-30T07:00:00Z 1950-04-30 03:00:00 -05:00 → -04:00 EDT Yes gap
1950-11-26T06:00:00Z 1950-11-26 01:00:00 -04:00 → -05:00 EST No overlap
1951-04-29T07:00:00Z 1951-04-29 03:00:00 -05:00 → -04:00 EDT Yes gap
1951-09-30T06:00:00Z 1951-09-30 01:00:00 -04:00 → -05:00 EST No overlap
1952-04-27T07:00:00Z 1952-04-27 03:00:00 -05:00 → -04:00 EDT Yes gap
1952-09-28T06:00:00Z 1952-09-28 01:00:00 -04:00 → -05:00 EST No overlap
1953-04-26T07:00:00Z 1953-04-26 03:00:00 -05:00 → -04:00 EDT Yes gap
1953-09-27T06:00:00Z 1953-09-27 01:00:00 -04:00 → -05:00 EST No overlap
1954-04-25T07:00:00Z 1954-04-25 03:00:00 -05:00 → -04:00 EDT Yes gap
1954-09-26T06:00:00Z 1954-09-26 01:00:00 -04:00 → -05:00 EST No overlap
1955-04-24T07:00:00Z 1955-04-24 03:00:00 -05:00 → -04:00 EDT Yes gap
1955-09-25T06:00:00Z 1955-09-25 01:00:00 -04:00 → -05:00 EST No overlap
1956-04-29T07:00:00Z 1956-04-29 03:00:00 -05:00 → -04:00 EDT Yes gap
1956-09-30T06:00:00Z 1956-09-30 01:00:00 -04:00 → -05:00 EST No overlap
1957-04-28T07:00:00Z 1957-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1957-10-27T06:00:00Z 1957-10-27 01:00:00 -04:00 → -05:00 EST No overlap
1958-04-27T07:00:00Z 1958-04-27 03:00:00 -05:00 → -04:00 EDT Yes gap
1958-10-26T06:00:00Z 1958-10-26 01:00:00 -04:00 → -05:00 EST No overlap
1959-04-26T07:00:00Z 1959-04-26 03:00:00 -05:00 → -04:00 EDT Yes gap
1959-10-25T06:00:00Z 1959-10-25 01:00:00 -04:00 → -05:00 EST No overlap
1960-04-24T07:00:00Z 1960-04-24 03:00:00 -05:00 → -04:00 EDT Yes gap
1960-10-30T06:00:00Z 1960-10-30 01:00:00 -04:00 → -05:00 EST No overlap
1961-04-30T07:00:00Z 1961-04-30 03:00:00 -05:00 → -04:00 EDT Yes gap
1961-10-29T06:00:00Z 1961-10-29 01:00:00 -04:00 → -05:00 EST No overlap
1962-04-29T07:00:00Z 1962-04-29 03:00:00 -05:00 → -04:00 EDT Yes gap
1962-10-28T06:00:00Z 1962-10-28 01:00:00 -04:00 → -05:00 EST No overlap
1963-04-28T07:00:00Z 1963-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1963-10-27T06:00:00Z 1963-10-27 01:00:00 -04:00 → -05:00 EST No overlap
1964-04-26T07:00:00Z 1964-04-26 03:00:00 -05:00 → -04:00 EDT Yes gap
1964-10-25T06:00:00Z 1964-10-25 01:00:00 -04:00 → -05:00 EST No overlap
1965-04-25T07:00:00Z 1965-04-25 03:00:00 -05:00 → -04:00 EDT Yes gap
1965-10-31T06:00:00Z 1965-10-31 01:00:00 -04:00 → -05:00 EST No overlap
1966-04-24T07:00:00Z 1966-04-24 03:00:00 -05:00 → -04:00 EDT Yes gap
1966-10-30T06:00:00Z 1966-10-30 01:00:00 -04:00 → -05:00 EST No overlap
1967-04-30T07:00:00Z 1967-04-30 03:00:00 -05:00 → -04:00 EDT Yes gap
1967-10-29T06:00:00Z 1967-10-29 01:00:00 -04:00 → -05:00 EST No overlap
1968-04-28T07:00:00Z 1968-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1968-10-27T06:00:00Z 1968-10-27 01:00:00 -04:00 → -05:00 EST No overlap
1969-04-27T07:00:00Z 1969-04-27 03:00:00 -05:00 → -04:00 EDT Yes gap
1969-10-26T06:00:00Z 1969-10-26 01:00:00 -04:00 → -05:00 EST No overlap
1970-04-26T07:00:00Z 1970-04-26 03:00:00 -05:00 → -04:00 EDT Yes gap
1970-10-25T06:00:00Z 1970-10-25 01:00:00 -04:00 → -05:00 EST No overlap
1971-04-25T07:00:00Z 1971-04-25 03:00:00 -05:00 → -04:00 EDT Yes gap
1971-10-31T06:00:00Z 1971-10-31 01:00:00 -04:00 → -05:00 EST No overlap
1972-04-30T07:00:00Z 1972-04-30 03:00:00 -05:00 → -04:00 EDT Yes gap
1972-10-29T06:00:00Z 1972-10-29 01:00:00 -04:00 → -05:00 EST No overlap
1973-04-29T07:00:00Z 1973-04-29 03:00:00 -05:00 → -04:00 EDT Yes gap
1973-10-28T06:00:00Z 1973-10-28 01:00:00 -04:00 → -05:00 EST No overlap
1974-04-28T07:00:00Z 1974-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1974-10-27T06:00:00Z 1974-10-27 01:00:00 -04:00 → -05:00 EST No overlap
1975-04-27T07:00:00Z 1975-04-27 03:00:00 -05:00 → -04:00 EDT Yes gap
1975-10-26T06:00:00Z 1975-10-26 01:00:00 -04:00 → -05:00 EST No overlap
1976-04-25T07:00:00Z 1976-04-25 03:00:00 -05:00 → -04:00 EDT Yes gap
1976-10-31T06:00:00Z 1976-10-31 01:00:00 -04:00 → -05:00 EST No overlap
1977-04-24T07:00:00Z 1977-04-24 03:00:00 -05:00 → -04:00 EDT Yes gap
1977-10-30T06:00:00Z 1977-10-30 01:00:00 -04:00 → -05:00 EST No overlap
1978-04-30T07:00:00Z 1978-04-30 03:00:00 -05:00 → -04:00 EDT Yes gap
1978-10-29T06:00:00Z 1978-10-29 01:00:00 -04:00 → -05:00 EST No overlap
1979-04-29T07:00:00Z 1979-04-29 03:00:00 -05:00 → -04:00 EDT Yes gap
1979-10-28T06:00:00Z 1979-10-28 01:00:00 -04:00 → -05:00 EST No overlap
1980-04-27T07:00:00Z 1980-04-27 03:00:00 -05:00 → -04:00 EDT Yes gap
1980-10-26T06:00:00Z 1980-10-26 01:00:00 -04:00 → -05:00 EST No overlap
1981-04-26T07:00:00Z 1981-04-26 03:00:00 -05:00 → -04:00 EDT Yes gap
1981-10-25T06:00:00Z 1981-10-25 01:00:00 -04:00 → -05:00 EST No overlap
1982-04-25T07:00:00Z 1982-04-25 03:00:00 -05:00 → -04:00 EDT Yes gap
1982-10-31T06:00:00Z 1982-10-31 01:00:00 -04:00 → -05:00 EST No overlap
1983-04-24T07:00:00Z 1983-04-24 03:00:00 -05:00 → -04:00 EDT Yes gap
1983-10-30T06:00:00Z 1983-10-30 01:00:00 -04:00 → -05:00 EST No overlap
1984-04-29T07:00:00Z 1984-04-29 03:00:00 -05:00 → -04:00 EDT Yes gap
1984-10-28T06:00:00Z 1984-10-28 01:00:00 -04:00 → -05:00 EST No overlap
1985-04-28T07:00:00Z 1985-04-28 03:00:00 -05:00 → -04:00 EDT Yes gap
1985-10-27T06:00:00Z 1985-10-27 01:00:00 -04:00 → -05:00 EST No overlap
1986-04-27T07:00:00Z 1986-04-27 03:00:00 -05:00 → -04:00 EDT Yes gap
1986-10-26T06:00:00Z 1986-10-26 01:00:00 -04:00 → -05:00 EST No overlap
1987-04-05T07:00:00Z 1987-04-05 03:00:00 -05:00 → -04:00 EDT Yes gap
1987-10-25T06:00:00Z 1987-10-25 01:00:00 -04:00 → -05:00 EST No overlap
1988-04-03T07:00:00Z 1988-04-03 03:00:00 -05:00 → -04:00 EDT Yes gap
1988-10-30T06:00:00Z 1988-10-30 01:00:00 -04:00 → -05:00 EST No overlap
1989-04-02T07:00:00Z 1989-04-02 03:00:00 -05:00 → -04:00 EDT Yes gap
1989-10-29T06:00:00Z 1989-10-29 01:00:00 -04:00 → -05:00 EST No overlap
1990-04-01T07:00:00Z 1990-04-01 03:00:00 -05:00 → -04:00 EDT Yes gap
1990-10-28T06:00:00Z 1990-10-28 01:00:00 -04:00 → -05:00 EST No overlap
1991-04-07T07:00:00Z 1991-04-07 03:00:00 -05:00 → -04:00 EDT Yes gap
1991-10-27T06:00:00Z 1991-10-27 01:00:00 -04:00 → -05:00 EST No overlap
1992-04-05T07:00:00Z 1992-04-05 03:00:00 -05:00 → -04:00 EDT Yes gap
1992-10-25T06:00:00Z 1992-10-25 01:00:00 -04:00 → -05:00 EST No overlap
1993-04-04T07:00:00Z 1993-04-04 03:00:00 -05:00 → -04:00 EDT Yes gap
1993-10-31T06:00:00Z 1993-10-31 01:00:00 -04:00 → -05:00 EST No overlap
1994-04-03T07:00:00Z 1994-04-03 03:00:00 -05:00 → -04:00 EDT Yes gap
1994-10-30T06:00:00Z 1994-10-30 01:00:00 -04:00 → -05:00 EST No overlap
1995-04-02T07:00:00Z 1995-04-02 03:00:00 -05:00 → -04:00 EDT Yes gap
1995-10-29T06:00:00Z 1995-10-29 01:00:00 -04:00 → -05:00 EST No overlap
1996-04-07T07:00:00Z 1996-04-07 03:00:00 -05:00 → -04:00 EDT Yes gap
1996-10-27T06:00:00Z 1996-10-27 01:00:00 -04:00 → -05:00 EST No overlap
1997-04-06T07:00:00Z 1997-04-06 03:00:00 -05:00 → -04:00 EDT Yes gap
1997-10-26T06:00:00Z 1997-10-26 01:00:00 -04:00 → -05:00 EST No overlap
1998-04-05T07:00:00Z 1998-04-05 03:00:00 -05:00 → -04:00 EDT Yes gap
1998-10-25T06:00:00Z 1998-10-25 01:00:00 -04:00 → -05:00 EST No overlap
1999-04-04T07:00:00Z 1999-04-04 03:00:00 -05:00 → -04:00 EDT Yes gap
1999-10-31T06:00:00Z 1999-10-31 01:00:00 -04:00 → -05:00 EST No overlap
2000-04-02T07:00:00Z 2000-04-02 03:00:00 -05:00 → -04:00 EDT Yes gap
2000-10-29T06:00:00Z 2000-10-29 01:00:00 -04:00 → -05:00 EST No overlap
2001-04-01T07:00:00Z 2001-04-01 03:00:00 -05:00 → -04:00 EDT Yes gap
2001-10-28T06:00:00Z 2001-10-28 01:00:00 -04:00 → -05:00 EST No overlap
2002-04-07T07:00:00Z 2002-04-07 03:00:00 -05:00 → -04:00 EDT Yes gap
2002-10-27T06:00:00Z 2002-10-27 01:00:00 -04:00 → -05:00 EST No overlap
2003-04-06T07:00:00Z 2003-04-06 03:00:00 -05:00 → -04:00 EDT Yes gap
2003-10-26T06:00:00Z 2003-10-26 01:00:00 -04:00 → -05:00 EST No overlap
2004-04-04T07:00:00Z 2004-04-04 03:00:00 -05:00 → -04:00 EDT Yes gap
2004-10-31T06:00:00Z 2004-10-31 01:00:00 -04:00 → -05:00 EST No overlap
2005-04-03T07:00:00Z 2005-04-03 03:00:00 -05:00 → -04:00 EDT Yes gap
2005-10-30T06:00:00Z 2005-10-30 01:00:00 -04:00 → -05:00 EST No overlap
2006-04-02T07:00:00Z 2006-04-02 03:00:00 -05:00 → -04:00 EDT Yes gap
2006-10-29T06:00:00Z 2006-10-29 01:00:00 -04:00 → -05:00 EST No overlap
2007-03-11T07:00:00Z 2007-03-11 03:00:00 -05:00 → -04:00 EDT Yes gap
2007-11-04T06:00:00Z 2007-11-04 01:00:00 -04:00 → -05:00 EST No overlap
2008-03-09T07:00:00Z 2008-03-09 03:00:00 -05:00 → -04:00 EDT Yes gap
2008-11-02T06:00:00Z 2008-11-02 01:00:00 -04:00 → -05:00 EST No overlap
2009-03-08T07:00:00Z 2009-03-08 03:00:00 -05:00 → -04:00 EDT Yes gap
2009-11-01T06:00:00Z 2009-11-01 01:00:00 -04:00 → -05:00 EST No overlap
2010-03-14T07:00:00Z 2010-03-14 03:00:00 -05:00 → -04:00 EDT Yes gap
2010-11-07T06:00:00Z 2010-11-07 01:00:00 -04:00 → -05:00 EST No overlap
2011-03-13T07:00:00Z 2011-03-13 03:00:00 -05:00 → -04:00 EDT Yes gap
2011-11-06T06:00:00Z 2011-11-06 01:00:00 -04:00 → -05:00 EST No overlap
2012-03-11T07:00:00Z 2012-03-11 03:00:00 -05:00 → -04:00 EDT Yes gap
2012-11-04T06:00:00Z 2012-11-04 01:00:00 -04:00 → -05:00 EST No overlap
2013-03-10T07:00:00Z 2013-03-10 03:00:00 -05:00 → -04:00 EDT Yes gap
2013-11-03T06:00:00Z 2013-11-03 01:00:00 -04:00 → -05:00 EST No overlap
2014-03-09T07:00:00Z 2014-03-09 03:00:00 -05:00 → -04:00 EDT Yes gap
2014-11-02T06:00:00Z 2014-11-02 01:00:00 -04:00 → -05:00 EST No overlap
2015-03-08T07:00:00Z 2015-03-08 03:00:00 -05:00 → -04:00 EDT Yes gap
2015-11-01T06:00:00Z 2015-11-01 01:00:00 -04:00 → -05:00 EST No overlap
2016-03-13T07:00:00Z 2016-03-13 03:00:00 -05:00 → -04:00 EDT Yes gap
2016-11-06T06:00:00Z 2016-11-06 01:00:00 -04:00 → -05:00 EST No overlap
2017-03-12T07:00:00Z 2017-03-12 03:00:00 -05:00 → -04:00 EDT Yes gap
2017-11-05T06:00:00Z 2017-11-05 01:00:00 -04:00 → -05:00 EST No overlap
2018-03-11T07:00:00Z 2018-03-11 03:00:00 -05:00 → -04:00 EDT Yes gap
2018-11-04T06:00:00Z 2018-11-04 01:00:00 -04:00 → -05:00 EST No overlap
2019-03-10T07:00:00Z 2019-03-10 03:00:00 -05:00 → -04:00 EDT Yes gap
2019-11-03T06:00:00Z 2019-11-03 01:00:00 -04:00 → -05:00 EST No overlap
2020-03-08T07:00:00Z 2020-03-08 03:00:00 -05:00 → -04:00 EDT Yes gap
2020-11-01T06:00:00Z 2020-11-01 01:00:00 -04:00 → -05:00 EST No overlap
2021-03-14T07:00:00Z 2021-03-14 03:00:00 -05:00 → -04:00 EDT Yes gap
2021-11-07T06:00:00Z 2021-11-07 01:00:00 -04:00 → -05:00 EST No overlap
2022-03-13T07:00:00Z 2022-03-13 03:00:00 -05:00 → -04:00 EDT Yes gap
2022-11-06T06:00:00Z 2022-11-06 01:00:00 -04:00 → -05:00 EST No overlap
2023-03-12T07:00:00Z 2023-03-12 03:00:00 -05:00 → -04:00 EDT Yes gap
2023-11-05T06:00:00Z 2023-11-05 01:00:00 -04:00 → -05:00 EST No overlap
2024-03-10T07:00:00Z 2024-03-10 03:00:00 -05:00 → -04:00 EDT Yes gap
2024-11-03T06:00:00Z 2024-11-03 01:00:00 -04:00 → -05:00 EST No overlap
2025-03-09T07:00:00Z 2025-03-09 03:00:00 -05:00 → -04:00 EDT Yes gap
2025-11-02T06:00:00Z 2025-11-02 01:00:00 -04:00 → -05:00 EST No overlap
2026-03-08T07:00:00Z 2026-03-08 03:00:00 -05:00 → -04:00 EDT Yes gap
2026-11-01T06:00:00Z 2026-11-01 01:00:00 -04:00 → -05:00 EST No overlap
2027-03-14T07:00:00Z 2027-03-14 03:00:00 -05:00 → -04:00 EDT Yes gap
2027-11-07T06:00:00Z 2027-11-07 01:00:00 -04:00 → -05:00 EST No overlap
2028-03-12T07:00:00Z 2028-03-12 03:00:00 -05:00 → -04:00 EDT Yes gap
2028-11-05T06:00:00Z 2028-11-05 01:00:00 -04:00 → -05:00 EST No overlap
2029-03-11T07:00:00Z 2029-03-11 03:00:00 -05:00 → -04:00 EDT Yes gap
2029-11-04T06:00:00Z 2029-11-04 01:00:00 -04:00 → -05:00 EST No overlap
2030-03-10T07:00:00Z 2030-03-10 03:00:00 -05:00 → -04:00 EDT Yes gap
2030-11-03T06:00:00Z 2030-11-03 01:00:00 -04:00 → -05:00 EST No overlap
2031-03-09T07:00:00Z 2031-03-09 03:00:00 -05:00 → -04:00 EDT Yes gap
2031-11-02T06:00:00Z 2031-11-02 01:00:00 -04:00 → -05:00 EST No overlap
2032-03-14T07:00:00Z 2032-03-14 03:00:00 -05:00 → -04:00 EDT Yes gap
2032-11-07T06:00:00Z 2032-11-07 01:00:00 -04:00 → -05:00 EST No overlap
2033-03-13T07:00:00Z 2033-03-13 03:00:00 -05:00 → -04:00 EDT Yes gap
2033-11-06T06:00:00Z 2033-11-06 01:00:00 -04:00 → -05:00 EST No overlap
2034-03-12T07:00:00Z 2034-03-12 03:00:00 -05:00 → -04:00 EDT Yes gap
2034-11-05T06:00:00Z 2034-11-05 01:00:00 -04:00 → -05:00 EST No overlap
2035-03-11T07:00:00Z 2035-03-11 03:00:00 -05:00 → -04:00 EDT Yes gap
2035-11-04T06:00:00Z 2035-11-04 01:00:00 -04:00 → -05:00 EST No overlap
2036-03-09T07:00:00Z 2036-03-09 03:00:00 -05:00 → -04:00 EDT Yes gap
2036-11-02T06:00:00Z 2036-11-02 01:00:00 -04:00 → -05:00 EST No overlap
2037-03-08T07:00:00Z 2037-03-08 03:00:00 -05:00 → -04:00 EDT Yes gap
2037-11-01T06:00:00Z 2037-11-01 01:00:00 -04:00 → -05:00 EST No overlap

Notes from the Maintainers

Source: backzone (Lines 877 to 917)
Canada

From Paul Eggert (2003-07-27):
Willett (1914-03) writes (p. 17) "In the Cities of Fort William, and
Port Arthur, Ontario, the principle of the Bill has been in
operation for the past three years, and in the City of Moose Jaw,
Saskatchewan, for one year."

From David Bryan via Tory Tronrud, Director/Curator,
Thunder Bay Museum (2003-11-12):
There is some suggestion, however, that, by-law or not, daylight
savings time was being practiced in Fort William and Port Arthur
before 1909.... [I]n 1910, the line between the Eastern and Central
Time Zones was permanently moved about two hundred miles west to
include the Thunder Bay area....  When Canada adopted daylight
savings time in 1916, Fort William and Port Arthur, having done so
already, did not change their clocks....  During the Second World
War,... [t]he cities agreed to implement DST during the summer
months for the remainder of the war years.

From Jeffery Nichols (2020-02-06):
According to the [Shanks] atlas, those western Ontario zones are huge,
covering most of Ontario northwest of Sault Ste Marie and Timmins.
The zones seem to include towns bigger than the ones they're named after,
like Dryden in America/Rainy_River and Wawa (and maybe Attawapiskat) in
America/Nipigon.  I assume it's too much trouble to change the name of the
zone (like when you found out that America/Glace_Bay includes Sydney, Nova
Scotia)....

From Chris Walton (2022-10-15):
The TZ database currently shows that Thunder Bay has observed daylight
saving every year from 1970 onwards with the exception of 1973.
Back in July I raised some doubts on this mailing list about the 1973 data.
I now have more proof that it is wrong.
[attached Chronicle-Journal front pages, 1973-04-28 and 1973-10-27]

From Paul Eggert (2022-10-15):
This is now a link in the primary data.  The following entry is
from Shanks & Pottenger, with corrections as noted above.

Attributed Statements:

Paul Eggert (2003-07-27):

Willett (1914-03) writes (p. 17) "In the Cities of Fort William, and Port Arthur, Ontario, the principle of the Bill has been in operation for the past three years, and in the City of Moose Jaw, Saskatchewan, for one year." From David Bryan via Tory Tronrud, Director/Curator, Thunder Bay Museum (2003-11-12): There is some suggestion, however, that, by-law or not, daylight savings time was being practiced in Fort William and Port Arthur before 1909.... [I]n 1910, the line between the Eastern and Central Time Zones was permanently moved about two hundred miles west to include the Thunder Bay area.... When Canada adopted daylight savings time in 1916, Fort William and Port Arthur, having done so already, did not change their clocks.... During the Second World War,... [t]he cities agreed to implement DST during the summer months for the remainder of the war years.

Jeffery Nichols (2020-02-06):

According to the [Shanks] atlas, those western Ontario zones are huge, covering most of Ontario northwest of Sault Ste Marie and Timmins. The zones seem to include towns bigger than the ones they're named after, like Dryden in America/Rainy_River and Wawa (and maybe Attawapiskat) in America/Nipigon. I assume it's too much trouble to change the name of the zone (like when you found out that America/Glace_Bay includes Sydney, Nova Scotia)....

Chris Walton (2022-10-15):

The TZ database currently shows that Thunder Bay has observed daylight saving every year from 1970 onwards with the exception of 1973. Back in July I raised some doubts on this mailing list about the 1973 data. I now have more proof that it is wrong. [attached Chronicle-Journal front pages, 1973-04-28 and 1973-10-27]

Paul Eggert (2022-10-15):

This is now a link in the primary data. The following entry is from Shanks & Pottenger, with corrections as noted above.

Years on Record

Methodology Note: The 1970 Rule

tzdb guarantees accuracy for timestamps from 1970 onwards. Transitions prior to 1970 represent best-effort historical reconstructions.