AST to CAT
+6hAST
ASTSOURCECAT
CATGreen rows indicate typical business hours (9 AM - 5 PM)
AST and CAT on the World Map
The map below highlights the AST (Atlantic Standard Time) and CAT (Central Africa Time) timezone regions across the globe.
AST – Atlantic Standard Time
UTC-04:00Atlantic Standard Time (AST) is the time zone for the Canadian Atlantic provinces and the Caribbean, 4 hours behind UTC.
- •Puerto Rico uses AST year-round and does not observe DST.
- •AST is 1 hour ahead of EST.
- •Halifax, the capital of Nova Scotia, is the largest city in AST Canada.
CAT – Central Africa Time
UTC+02:00Central Africa Time (CAT, UTC+02:00) covers Zimbabwe, Zambia, Mozambique, Malawi and neighbouring countries.
- •Central Africa Time is fixed at UTC+02:00 with no daylight saving.
- •CAT matches South Africa Standard Time (SAST) all year.
- •It is the same offset as Central European Time in winter.
- •Harare is level with Johannesburg and one hour ahead of Lagos.
Understanding the +6h Gap: AST vs CAT
AST runs on Atlantic Standard Time (AST) at UTC-04:00. CAT runs on Central Africa Time (CAT) at UTC+02:00. That puts AST 6 hours ahead of CAT — a difference of +6h at the current offsets.
In practice, when it is 9:00 AM in AST it is 3:00 PM in CAT. Midnight in AST is 6:00 AM in CAT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
AST to CAT time conversion table
| AST (AST) | CAT (CAT) | Day |
|---|---|---|
| 12:00 AM | 6:00 AM | same day |
| 6:00 AM | 12:00 PM | same day |
| 7:00 AM | 1:00 PM | same day |
| 8:00 AM | 2:00 PM | same day |
| 9:00 AM | 3:00 PM | same day |
| 12:00 PM | 6:00 PM | same day |
| 3:00 PM | 9:00 PM | same day |
| 5:00 PM | 11:00 PM | same day |
| 6:00 PM | 12:00 AM | next day |
| 9:00 PM | 3:00 AM | next day |
Why people convert AST to CAT time
- Scheduling a call from AST to CAT: a 10:00 AM start in AST lands at 4:00 PM in CAT, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both AST and CAT are inside the 9-to-5 working day between 9:00 AM and 11:00 AM AST time (3:00 PM–5:00 PM CAT). That is roughly 2 hours of usable overlap.
- Coordinating a AST-based team with CAT contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
- Always state the zone abbreviation, not just the hour. "3:00 PM AST" is unambiguous; "3 PM" across a +6h gap is not.
- Block 9:00 AM–11:00 AM AST as the recurring meeting window if you work primarily from AST and need CAT colleagues present.
About AST (Atlantic Standard Time)
Atlantic Standard Time (AST) covers Canada's Atlantic provinces (Nova Scotia, New Brunswick, Prince Edward Island, and most of Labrador), as well as several Caribbean nations. Puerto Rico and the US Virgin Islands use AST year-round without daylight saving time. The Canadian provinces switch to Atlantic Daylight Time (ADT) in summer.
About CAT (Central Africa Time)
Central Africa Time (CAT) is fixed at UTC+02:00 all year across a broad belt of southern and central Africa, including Zimbabwe, Zambia, Mozambique, Malawi, Rwanda, Burundi and the eastern Democratic Republic of the Congo. None of these countries observes daylight saving time, so CAT never shifts. It is the same offset as South Africa Standard Time (SAST) and the winter version of Central European Time, which makes CAT a convenient bridge between African, European and Middle Eastern schedules — Harare is level with Johannesburg all year and one hour ahead of Lagos.
Best time to call between AST and CAT
Both AST and CAT sit inside the 9 AM – 5 PM working day between 9:00 AM–11:00 AM AST, which is 3:00 PM–5:00 PM CAT. That gives roughly 2 hours of shared time — the safest window for a live call or meeting.
Business hours overlap
AST and CAT overlap for about 2 hours during the working day — enough for meetings if you avoid the edges of the window.
AST is 6 hours ahead of CAT (AST UTC-04:00 → CAT UTC+02:00). The shared working window is 9:00 AM–11:00 AM AST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
AST
☀ Currently in DST
Standard: UTC-04:00 · DST: UTC-03:00
Clocks fall back on Sun, Nov 1, 2026
CAT
Does not observe DST
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between AST and CAT?
AST (AST, UTC-04:00) is 6 hours ahead of CAT (CAT, UTC+02:00). The gap is currently +6h.
How do I convert AST time to CAT time?
Add +6h to AST local time. For example, 9:00 AM in AST is 3:00 PM in CAT.
What time is it in CAT right now?
CAT uses CAT at UTC+02:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +6h offset from AST.
What is the best time to call CAT from AST?
Call between 9:00 AM and 11:00 AM AST — that maps to 3:00 PM–5:00 PM CAT and keeps both parties inside the working day.
Which is ahead, AST or CAT?
AST is 6 hours ahead of CAT. When it is 12:00 PM in AST it is 6:00 PM in CAT.
Does daylight saving time affect the AST–CAT difference?
Neither zone observes daylight saving time, so the +6h offset between AST and CAT is fixed all year.
Which other cities share AST's time zone?
AST also covers Halifax, San Juan, Santo Domingo, Caracas, La Paz, Fredericton, Charlottetown.
Which countries use AST, AST's zone?
AST is used in Canada (Atlantic provinces), Puerto Rico, US Virgin Islands, Dominican Republic, Venezuela, Bolivia, Barbados, Trinidad and Tobago.
Is there a day difference between AST and CAT?
Not normally. The +6h gap only pushes the date over for late-evening times.
What is the time difference between AST and CAT?
CAT is +6h from AST.
What timezone is AST in?
AST operates on its local timezone.
What timezone is CAT in?
CAT operates on its local timezone.
Which countries use AST (Atlantic Standard Time)?
AST is used in Canada (Atlantic provinces), Puerto Rico, US Virgin Islands, Dominican Republic, Venezuela, Bolivia, and 2 more countries.
Does AST observe daylight saving time?
Yes, AST switches to ADT during summer months.
What are some interesting facts about AST?
Puerto Rico uses AST year-round and does not observe DST. AST is 1 hour ahead of EST.
Which cities are in the CAT timezone?
Major cities in the CAT timezone include Harare, Lusaka, Maputo, Lilongwe, Kigali.
What is the UTC offset for CAT?
Central Africa Time (CAT) is at UTC+02:00.
What should I know about the CAT timezone?
Central Africa Time is fixed at UTC+02:00 with no daylight saving. CAT matches South Africa Standard Time (SAST) all year.
When is it midnight in AST, what time is it in CAT?
When it is 12:00 AM (midnight) in AST (AST), it is +6h later in CAT (CAT).
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See every conversion from AST →·See every conversion from CAT →