Convert Eastern Time to GMT in seconds
This tool converts U.S. Eastern Time (ET) into GMT/UTC quickly and clearly. Just enter a date, enter a time, and choose whether you want automatic daylight saving handling or a fixed offset.
If you're coordinating remote work, webinars, customer support windows, flights, or international deadlines, this conversion helps prevent missed meetings and scheduling confusion.
Eastern Time vs GMT: the simple version
- EST = GMT-5 (Eastern Standard Time, winter)
- EDT = GMT-4 (Eastern Daylight Time, summer)
- ET is a general label and can mean EST or EDT depending on the date
| Eastern Time | Offset Used | GMT Result |
|---|---|---|
| 8:00 AM EST | +5 hours | 1:00 PM GMT |
| 8:00 AM EDT | +4 hours | 12:00 PM GMT |
| 11:30 PM EST | +5 hours | 4:30 AM GMT (next day) |
How to use this calculator
1) Enter date and time
Start with the local Eastern date and time you want to convert.
2) Pick a mode
- Auto: best for most users; switches EST/EDT using daylight saving rules.
- EST: always UTC-5.
- EDT: always UTC-4.
3) Click convert
You’ll get the GMT result, the offset used, and clean date/time output that’s easy to copy into messages or calendars.
Why this matters for global scheduling
Time zone mistakes often happen around daylight saving changes. A one-hour error can affect client calls, virtual events, payment cutoffs, and team handoffs. Using a dedicated ET to GMT calculator lowers that risk and keeps everyone aligned.
Daylight saving edge cases
Two moments in the year can be tricky:
- Spring forward (March): times between 2:00 AM and 2:59 AM may not exist.
- Fall back (November): times between 1:00 AM and 1:59 AM can occur twice.
This calculator flags these edge windows in Auto mode so you can confirm the intended meeting time.
Quick FAQ
Is GMT the same as UTC?
For everyday scheduling, yes. GMT and UTC are usually treated as equivalent in practical business use.
Do I always add 5 hours to Eastern time?
Not always. Add 5 hours during EST and 4 hours during EDT.
Can I use this for London time?
You can convert ET to GMT/UTC here. London may use BST (British Summer Time), which is UTC+1 in summer, so check local UK daylight rules for final local-time scheduling.