America/Blanc-Sablon

Time zone identifier: America/Blanc-Sablon

Current civil offset: -04:00 (AST)

Current DST state: Observing Standard Time

First standard time adoption: Adopted on 1884-01-01

Local Mean Time (LMT): -03:48:28 based on geographic meridian

Total recorded transitions: 6 transitions across 3 distinct offsets

Associated countries: CA

Historical Offset Step Chart (1880 to Present)

Text summary: America/Blanc-Sablon shifted between 3 distinct offsets from 1884-01-01 through the modern era.

Complete Transition History (6 Transitions)

UTC Instant	Local Wall Time	Shift	Abbreviation	DST	Effect
`1884-01-01T03:48:28Z`	`1883-12-31 23:48:28`	-03:48:28 → -04:00	`AST`	No	overlap
`1918-04-14T06:00:00Z`	`1918-04-14 03:00:00`	-04:00 → -03:00	`ADT`	Yes	gap
`1918-10-27T05:00:00Z`	`1918-10-27 01:00:00`	-03:00 → -04:00	`AST`	No	overlap
`1942-02-09T06:00:00Z`	`1942-02-09 03:00:00`	-04:00 → -03:00	`AWT`	Yes	gap
`1945-08-14T23:00:00Z`	`1945-08-14 20:00:00`	-03:00 → -03:00	`APT`	Yes	offset-only
`1945-09-30T05:00:00Z`	`1945-09-30 01:00:00`	-03:00 → -04:00	`AST`	No	overlap

Notes from the Maintainers

Source: backzone (Lines 509 to 529)

PACKRATLIST zone.tab Link America/Atikokan America/Coral_Harbour

Quebec east of Natashquan

From Paul Eggert (2021-05-09):
H. David Matthews and Mary Vincent's map
"It's about TIME", _Canadian Geographic_ (September-October 1998)
http://www.canadiangeographic.ca/Magazine/SO98/alacarte.asp
says that Quebec east of the -63 meridian is supposed to observe
AST, but residents as far east as Natashquan use EST/EDT, and
residents east of Natashquan use AST.
The Quebec department of justice writes in
"The situation in Minganie and Basse-Côte-Nord"
https://www.justice.gouv.qc.ca/en/department/ministre/functions-and-responsabilities/legal-time-in-quebec/the-situation-in-minganie-and-basse-cote-nord/
that the coastal strip from just east of Natashquan to Blanc-Sablon
observes Atlantic standard time all year round.
This common practice was codified into law as of 2007; see Legal Time Act,
CQLR c T-5.1 <http://legisquebec.gouv.qc.ca/en/ShowDoc/cs/T-5.1>.
For lack of better info, guess this practice began around 1970, contra to
Shanks & Pottenger who have this region observing AST/ADT.

Attributed Statements:

Paul Eggert (2021-05-09):

H. David Matthews and Mary Vincent's map "It's about TIME", _Canadian Geographic_ (September-October 1998) http://www.canadiangeographic.ca/Magazine/SO98/alacarte.asp says that Quebec east of the -63 meridian is supposed to observe AST, but residents as far east as Natashquan use EST/EDT, and residents east of Natashquan use AST. The Quebec department of justice writes in "The situation in Minganie and Basse-Côte-Nord" https://www.justice.gouv.qc.ca/en/department/ministre/functions-and-responsabilities/legal-time-in-quebec/the-situation-in-minganie-and-basse-cote-nord/ that the coastal strip from just east of Natashquan to Blanc-Sablon observes Atlantic standard time all year round. This common practice was codified into law as of 2007; see Legal Time Act, CQLR c T-5.1 <http://legisquebec.gouv.qc.ca/en/ShowDoc/cs/T-5.1>. For lack of better info, guess this practice began around 1970, contra to Shanks & Pottenger who have this region observing AST/ADT.

Methodology Note: The 1970 Rule

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