Convert Atlantic Standard Time to Central Daylight Time
Instantly convert Atlantic Standard Time (AST) to Central Daylight Time (CDT) with our free online calculator.
Atlantic Standard Time
01:20:48 AM
Wed, Jun 24 (AST)
Central Daylight Time
12:20:48 AM
Wed, Jun 24 (CDT)
Convert a Specific Time
24-Hour Comparison
| AST | CDT |
|---|---|
| 12:00 AM | 11:00 PM(-1d) |
| 1:00 AM | 12:00 AM |
| 2:00 AM | 1:00 AM |
| 3:00 AM | 2:00 AM |
| 4:00 AM | 3:00 AM |
| 5:00 AM | 4:00 AM |
| 6:00 AM | 5:00 AM |
| 7:00 AM | 6:00 AM |
| 8:00 AM | 7:00 AM |
| 9:00 AM | 8:00 AM |
| 10:00 AM | 9:00 AM |
| 11:00 AM | 10:00 AM |
| 12:00 PM | 11:00 AM |
| 1:00 PM | 12:00 PM |
| 2:00 PM | 1:00 PM |
| 3:00 PM | 2:00 PM |
| 4:00 PM | 3:00 PM |
| 5:00 PM | 4:00 PM |
| 6:00 PM | 5:00 PM |
| 7:00 PM | 6:00 PM |
| 8:00 PM | 7:00 PM |
| 9:00 PM | 8:00 PM |
| 10:00 PM | 9:00 PM |
| 11:00 PM | 10:00 PM |
How to Convert Atlantic Standard Time to Central Daylight Time
Formula
To convert Atlantic Standard Time (AST) to Central Daylight Time (CDT): Convert AST to CDT
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 Central Daylight Time (CDT)
Central Daylight Time (CDT, IANA: America/Chicago during DST window) is the summer-time variant of CST, set at UTC-5:00 — observed from the second Sunday in March to the first Sunday in November per the US Energy Policy Act of 2005. CDT shares the same UTC offset as Eastern Standard Time (EST), so during winter months Chicago/Dallas are one hour behind New York/Atlanta, but during summer months Chicago/Dallas are still one hour behind because both regions advance equally for DST. The 'spring forward / fall back' transition affects an estimated 311 million US residents annually per Census data. CDT is used in 16 US states partially or fully (Illinois, Texas, Wisconsin, Minnesota, Iowa, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Tennessee, Kansas, Nebraska, Oklahoma, North Dakota, South Dakota) and parts of Canada (Manitoba, western Ontario, Saskatchewan partial — Saskatchewan stays on CST year-round, an exception). Affects MLB season game scheduling, CME / CBOT commodity trading hours, and US-Canada-Mexico USMCA cross-border supply-chain handoffs.