Tehran
Iran Standard Time
--:--
London
British Summer Time
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The exact hour gap shifts with DST — dial it in below.
IRST → BST · DST-aware · ShareableIRST → BST · DST-aware
Convert IRST to BST, accurate & shareable.
Iran Standard Time (Tehran) and British Summer Time (London). Live offsets, preset deadlines, hour-by-hour comparison, FAQs, plus a URL that encodes your exact pick—the converter below narrows dates and stays DST-correct across both zones.
1
Live clocks
See current time in Tehran (IRST) and London (BST) with active DST rules.
2
Set a deadline
Pick date and civil time in the workspace—offsets and day-shift cues update instantly for your selection.
3
Share or explore
Copy a shareable URL, scan the 24-hour table below, or open related conversion and deadline routes.
About this pair
IRST → BST at a glance
Convert IRST to BST — Iran Standard Time (Tehran) is currently 3.5 hours ahead of British Summer Time (London). A 9 AM IRST deadline lands at approximately 5:30 AM BST, and a 5 PM IRST deadline at 1:30 PM BST.
Because at least one of IRST or BST observes Daylight Saving Time, the offset gap shifts by an hour twice a year. The converter below uses the IANA timezone database to pick the correct offset for your selected deadline date.
Need another route? Browse the full conversions index (2,756 pairs) or open the two-zone converter.
Deadline workspace
Set the source, use the answer.
Live conversion
1
Source deadline
time and date the client gave you
2
Timezone route
Swap the direction any time if you are checking from your side.
Your local deadline
14:30
GMT+1 · 2026-06-23 · Tue
Source
17:00
GMT+3:30
Countdown
Deadline passed
Planning status
Business hours
Business hoursTue
Google CalendarHour-by-hour map
24-hour reference: IRST → BST
Every civil hour today from Tehran (IRST) translated into London (BST). Day badges mark midnight crossings; times follow your browser’s IANA database.
IRSTBST
Hourly wall-clock map for today — midnight crossings show as day shifts.
IRST with part-of-day icon
BST arrow and converted time
Day
- 00:0021:30Prev day
- 01:0022:30Prev day
- 02:0023:30Prev day
- 03:0000:30Same day
- 04:0001:30Same day
- 05:0002:30Same day
- 06:0003:30Same day
- 07:0004:30Same day
- 08:0005:30Same day
- 09:0006:30Same day
- 10:0007:30Same day
- 11:0008:30Same day
- 12:0009:30Same day
- 13:0010:30Same day
- 14:0011:30Same day
- 15:0012:30Same day
- 16:0013:30Same day
- 17:0014:30Same day
- 18:0015:30Same day
- 19:0016:30Same day
- 20:0017:30Same day
- 21:0018:30Same day
- 22:0019:30Same day
- 23:0020:30Same day
Uses your browser's IANA zone data — choose another date in the converter for historical or future days.
Preset shortcuts
Common deadlines
Five typical office times (morning through early evening) as a quick sanity check. Dial exact dates and share links in the converter workspace above.
IRSTBST
Shortcut rows for typical meeting hours — see the full 24-hour grid above.
IRST with part-of-day icon
BST arrow and converted time
Day
- 09:0006:30Same day
- 12:0009:30Same day
- 15:0012:30Same day
- 17:0014:30Same day
- 18:0015:30Same day
Uses your browser's IANA zone data — choose another date in the converter for historical or future days.
Quick open
Related conversions
Full pages with live clocks, 24-hour tables, preset deadlines, and FAQs—same chrome as IRST → BST. Browse all 2,756 conversion pages.
Straight answers
FAQ: IRST to BST
DST behaviour, sharing converted deadlines, and how these abbreviations tie to real cities and IANA zones.
The current difference depends on Daylight Saving Time in either zone. See the live converter above for the exact current offset.
Keep exploring
Related hubs & shortcuts
Deadline presets, more conversion pairs, city clocks, meeting overlap, and index pages—picked for this route so you can move on without searching.