Mumbai, India · UTC+5:30 ☆

India uses one clock for a country that spans 30 degrees of longitude, from Rann of Kutch in the west to the Arunachal Pradesh hills in the east. India Standard Time sits at UTC+5:30, that half-hour offset a deliberate split between the two whole-hour positions that would fit the country’s geography better. Mumbai, on India’s west coast, lives by the same clock as Kolkata two time zones east. At sunrise in Kolkata, Mumbai still has 90 minutes of darkness ahead.

India abolished daylight saving time in 1945 and has not used it since. The result is a clock that drifts out of solar sync across the country’s width. In Mumbai’s summer, the sun sets after 7:15pm, which feels right. In the winter it sets by 6:05pm, which feels early to anyone used to longer evenings.

None of this slows Mumbai down. The city of roughly 20 million operates at a pace and density that treats clock time as a suggestion more than a rule. The local trains run to the minute, carrying 7 million passengers a day on a network that has barely changed since the British built it. Everything else runs on “IST,” which locals sometimes call Indian Stretchable Time, a rueful acknowledgment that schedules flex.

Bollywood’s internal clock

The film industry, centered in the Film City complex in Goregaon, runs its own hours: shoots that start at noon and run past midnight, editing sessions at 3am, music recordings timed to avoid peak traffic. Bollywood’s internal clock has always been offset from the rest of the city.

9am in Mumbai is 3:30am in London, which means Mumbai’s morning overlap with European business hours is essentially zero. The city does its most globally connected work in its evenings.

Sources

• IANA Time Zone Database - Asia/Kolkata
• Municipal Corporation of Greater Mumbai