9am in Lisbon is 1:30pm in Mumbai

Mumbai is 4.5 hours ahead of Lisbon. Lisbon runs on Europe/Lisbon (UTC+1); Mumbai runs on Asia/Kolkata (UTC+5:30). The difference is measured right now; it can shift by one hour during daylight-saving-time transitions.

Lisbon observes daylight saving time — shifting between WET (UTC+0) and WEST (UTC+1) — while Mumbai stays on IST (UTC+5:30) year-round. The difference is 5.5 hours in Lisbon’s winter and 4.5 hours in Lisbon’s summer. Transitions happen in late March and late October for most Northern-Hemisphere DST zones, and late September/early April for Southern-Hemisphere ones — check the current date against the city’s DST schedule before anchoring a meeting at the edge of those windows.

Standard 9-to-5 business hours in Lisbon and Mumbai overlap for roughly 3.5 hours a day. That window lands at 09:00–12:30 in Lisbon and 13:30–17:00 in Mumbai. Teams with real-time coordination needs anchor cross-city calls inside it: long enough to cover handovers, short enough that it forces crisp agendas. Outside that window, async is the default — shared docs, recorded updates, and scheduled follow-ups rather than live meetings.

When planning recurring meetings across Lisbon and Mumbai, pin them to one city’s local time rather than UTC or the other city’s clock. That way, the meeting time stays stable for the person anchoring the schedule, and the other side absorbs the one-hour drift during DST transitions. The alternative — a meeting pinned to the non-DST city — means the DST city sees the meeting time “move” twice a year, which is how recurring calendar invites end up at 7am on someone’s calendar in October.