BST to IST

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BST is the UK's summer offset (UTC+1); in winter the UK is on GMT. See that conversion →

IST here means India Standard Time (UTC+5:30) — not Irish or Israel time.

What is the BST to IST time difference?

IST is 4 hours 30 minutes ahead of BST. BST is British Summer Time at a fixed UTC+1, and IST is India Standard Time at UTC+5:30. Because both are named constant offsets rather than city clocks, the gap does not move — the 24-hour table above reads the same every day of the year. To convert by hand, add 4 hours 30 minutes to the BST time.

What time is 9 AM BST in IST?

9 AM BST is 1:30 PM IST. That follows from the gap of 4 hours 30 minutes between UTC+1 and UTC+5:30, so every BST hour moves by the same amount. The full 24-hour table above lists every hour, so you can convert any BST time to IST at a glance. Because both are fixed offsets, that mapping is identical on any date — there is no daylight-saving exception to remember.

Is BST ahead of or behind IST?

IST is 4 hours 30 minutes ahead of BST, which is the same as saying BST is 4 hours 30 minutes behind IST. That comes straight from the two offsets: UTC+1 for BST against UTC+5:30 for IST. So at the same instant, 9:00 AM on BST reads 1:30 PM on IST. Both are fixed named offsets, so the direction and the size of that gap hold all year.

Does BST to IST change with daylight saving?

The BST↔IST offset itself never changes: UTC+1 to UTC+5:30 is a constant 4 hours 30 minutes gap. Note: BST is the UK's summer offset (UTC+1); in winter the UK is on GMT. IST here means India Standard Time (UTC+5:30) — not Irish or Israel time. What can change is which abbreviation a region is using at a given date, which is why the notes above link across to the matching conversion. Converting between the named offsets themselves, as this page does, is the same arithmetic on every day of the year.