Technical Specifications & Standards
Official chronometric properties, ISO standards, and international database registry identifiers for Newfoundland Standard Time:
Daylight Saving Time (DST) Transitions
⬆️ Spring Forward (Clocks Advance)
Clocks advance 1 hour to NDT on the second Sunday in March at 02:00
⬇️ Fall Back (Clocks Return)
Clocks return 1 hour to NST on the first Sunday in November at 02:00
Observing Jurisdictions & Subdivisions
1 Sovereign NationsSovereign nations, administrative subdivisions, and regional territories officially operating under NST:
Regional Subdivisions & Territory Details
Financial Markets & Trading Hours
Serves North Atlantic offshore oil extraction, transatlantic subsea fiber communications, and North American maritime fisheries.
Local Hours: 11:00 - 17:30 NST
UTC Window: 14:30 - 21:00 UTC
Major Cities in NST
Primary metropolitan centers and financial hubs observing this time zone:
Adoption History & Astronomical Facts
Year Established: 1935
When the Dominion of Newfoundland established standard time in 1935, authorities chose UTC-3:30 based on the 52.5° West meridian bisecting St. John's, creating a unique half-hour time zone that was preserved when Newfoundland joined Canadian Confederation in 1949.
Newfoundland is thirty minutes ahead of Atlantic Standard Time (AST, UTC-4), leading to the famous Canadian radio and television phrase: 'half an hour later in Newfoundland.'
Frequently Asked Questions about NST
What is Newfoundland Standard Time?
Newfoundland Standard Time (NST) is UTC-3:30, observed on the island of Newfoundland during winter.
Why is Newfoundland thirty minutes ahead of Atlantic Time?
The island standardized its clocks on its local solar meridian (52.5° West) in 1935, preserving the half-hour offset upon joining Canada in 1949.
What is the daylight saving counterpart to NST?
Newfoundland Daylight Time (NDT, UTC-2:30) is the summer counterpart to NST.