Convert Atlantic Standard Time to Coordinated Universal Time
Instantly convert Atlantic Standard Time (AST) to Coordinated Universal Time (UTC) with our free online calculator.
Atlantic Standard Time
01:20:48 AM
Wed, Jun 24 (AST)
Coordinated Universal Time
05:20:48 AM
Wed, Jun 24 (UTC)
Convert a Specific Time
24-Hour Comparison
| AST | UTC |
|---|---|
| 12:00 AM | 4:00 AM |
| 1:00 AM | 5:00 AM |
| 2:00 AM | 6:00 AM |
| 3:00 AM | 7:00 AM |
| 4:00 AM | 8:00 AM |
| 5:00 AM | 9:00 AM |
| 6:00 AM | 10:00 AM |
| 7:00 AM | 11:00 AM |
| 8:00 AM | 12:00 PM |
| 9:00 AM | 1:00 PM |
| 10:00 AM | 2:00 PM |
| 11:00 AM | 3:00 PM |
| 12:00 PM | 4:00 PM |
| 1:00 PM | 5:00 PM |
| 2:00 PM | 6:00 PM |
| 3:00 PM | 7:00 PM |
| 4:00 PM | 8:00 PM |
| 5:00 PM | 9:00 PM |
| 6:00 PM | 10:00 PM |
| 7:00 PM | 11:00 PM |
| 8:00 PM | 12:00 AM(+1d) |
| 9:00 PM | 1:00 AM(+1d) |
| 10:00 PM | 2:00 AM(+1d) |
| 11:00 PM | 3:00 AM(+1d) |
How to Convert Atlantic Standard Time to Coordinated Universal Time
Formula
To convert Atlantic Standard Time (AST) to Coordinated Universal Time (UTC): Convert AST to UTC
About Atlantic Standard Time (AST)
Atlantic Standard Time (AST, IANA: America/Halifax, America/Puerto_Rico) is the time zone for the Canadian Maritime provinces and most of the Caribbean, set at UTC-4:00. AST is observed in: Nova Scotia, New Brunswick, Prince Edward Island, Labrador (partially), Newfoundland's Labrador portion, eastern Quebec, Puerto Rico, US Virgin Islands, Bermuda, Anguilla, Antigua, Aruba, Barbados, British Virgin Islands, Curaçao, Dominica, Grenada, Guadeloupe, Martinique, Saint Lucia, Saint Vincent, Trinidad and Tobago, and Venezuela (since 2007). Canadian Maritime provinces observe AST in winter and switch to ADT = UTC-3:00 in summer per the Energy Policy Act-aligned Canadian schedule. The Caribbean territories (Puerto Rico, USVI, Bermuda) and US territories observe AST year-round without DST per their territorial governments. AST is the same offset as EDT (Eastern Daylight Time) during US summer months, so Halifax and New York are on the same clock in summer but Halifax is one hour ahead in winter.
About Coordinated Universal Time (UTC)
Coordinated Universal Time (UTC) is the primary time standard by which the world regulates clocks and time, defined since 1972 as the time at the Prime Meridian (0° longitude) maintained by BIPM (Bureau International des Poids et Mesures) in Sèvres, France. UTC is computed as a weighted average of approximately 400 atomic clocks at ~80 national metrology institutes (NIST in the US, NPL in UK, PTB in Germany, NICT in Japan, KRISS in Korea, etc.) per the formal definition in ITU-R Recommendation TF.460-6 (2002). UTC is functionally identical to GMT (Greenwich Mean Time) for civil purposes but differs slightly in its underlying timescale — UTC uses atomic seconds with occasional leap seconds inserted (announced by IERS Bulletin C ~6 months in advance, last leap second was December 31, 2016, and the system may be retired by 2035 per Resolution D of CGPM 2022). UTC is the standard for aviation (ICAO Annex 5), maritime navigation (IMO COLREGS), all internet protocols (NTP, PTP per IEEE 1588), all scientific publications, GPS / Galileo / GLONASS / BeiDou GNSS, and Universal Time on Wikipedia/Wikidata.