--:--:--
—
Chicago · Houston · Dallas
For international scheduling, try the timezone meeting planner.
Difference
AST vs CDT
UTC → UTC
--:--:--
—
San Juan · Barbados · Halifax (winter)
CDT to AST converter
Convert CDT to AST time now
Free CDT to AST converter. See Central Daylight Time and Atlantic Standard Time side by side. Live clocks, a 1 hour gap, meeting hours, and a full-day chart for Chicago and San Juan.
America/Chicago
—
CDT → AST
To · Atlantic Standard Time
—
America/Puerto_Rico
Interactive diagram
Watch CDT convert into AST
Drag the Central DT hour. Watch the Atlantic clock change.
Central DT
9:00 AM CDT
—
AST ← CDT
Atlantic
—
Full-day chart
CDT to AST hourly conversion chart
Full-day table. Tap a row to copy. Labels follow daylight saving.
| Central DT | Atlantic | UTC offsets |
|---|
Meeting times
Best CDT to AST meeting window
Find hours that work on both sides. Then save the slot to your calendar.
Follow along
Step-by-step CDT to AST conversion
Four short steps to convert any CDT time to AST.
Choose CDT time
Select any hour in Central Daylight Time. Smart mode uses America/Chicago.
CDT to AST conversion guide
CDT to AST conversion guide
This CDT to AST converter shows Atlantic Standard Time (UTC−4) for any Central Daylight Time (UTC−5) time. Use it to schedule between Chicago and San Juan. Choose Smart DST for live city clocks. Choose Fixed mode when you only want the CDT and AST labels.
Central DT
CDT
UTC−5
Chicago · Houston · Dallas
CDT vs AST—
Atlantic
AST
UTC−4
San Juan · Barbados · Halifax (winter)
What is CDT to AST conversion?
CDT to AST conversion turns a CDT clock into the matching AST time. Use it for calls, travel, and teams in Chicago and San Juan.
CDT to AST time difference
AST is 1 hour ahead of CDT. Add 1 hour to the CDT time to get AST. The live clocks at the top show the current CDT to AST gap.
CDT vs AST
CDT is UTC−5. AST is UTC−4. They are different names. If a region uses daylight saving, check the live labels.
CDT to AST now / current time
Need cdt to ast right now? Read the live clocks, or tap Use current time for an instant CDT → AST result.
CDT to AST time difference
Season / context — tap to explore
See how daylight saving can change this pair.
Central DT—
—CDT → AST
Atlantic—
Quick answers
Central DT
Central Daylight Time (CDT)
UTC−5
Central Daylight Time (CDT) is UTC−5. Smart DST uses the city clock America/Chicago so daylight saving stays correct for Chicago · Houston · Dallas.
- Cities: Chicago · Houston · Dallas
- City clock: America/Chicago
- Fixed CDT: UTC−5
- On this page it pairs with AST (UTC−4)
Atlantic
Atlantic Standard Time (AST)
UTC−4
Atlantic Standard Time (AST) is UTC−4. Smart DST uses America/Puerto_Rico for cities such as San Juan · Barbados · Halifax (winter).
- Cities: San Juan · Barbados · Halifax (winter)
- City clock: America/Puerto_Rico
- Fixed AST: UTC−4
- From CDT: AST is 1 hour ahead of CDT
CDT to AST FAQ