Timezone Calculator
Free Timezone Calculator for date & time. Enter your dates to calculate durations, differences, and countdowns broken down by years, months, days, and
Formula
Target Time = Source Time + (Target Offset - Source Offset)
Add the difference in UTC offsets between the source and target timezones. Positive offset means later time, negative means earlier. Handle day changes when crossing midnight.
Worked Examples
Example 1: US to Europe Call
Problem:Schedule a call at 9 AM New York time (EST). What time is it in London (GMT) and Paris (CET)?
Solution:New York (EST): 9:00 AM = UTC-5\n\nLondon (GMT): UTC+0\nOffset: 0 - (-5) = +5 hours\n9:00 AM + 5 hours = 2:00 PM GMT\n\nParis (CET): UTC+1\nOffset: 1 - (-5) = +6 hours\n9:00 AM + 6 hours = 3:00 PM CET
Result:London: 2:00 PM | Paris: 3:00 PM
Example 2: Asia to US Conversion
Problem:A flight departs Tokyo at 10:00 PM JST and takes 11 hours. What time does it arrive in Los Angeles (PST)?
Solution:Tokyo (JST): 10:00 PM = UTC+9\nLos Angeles (PST): UTC-8\n\nOffset difference: -8 - (+9) = -17 hours\n\nDeparture in LA time:\n10:00 PM - 17 hours = 5:00 AM (same day)\n\nAfter 11-hour flight:\n5:00 AM + 11 hours = 4:00 PM PST
Result:Arrives 4:00 PM PST (same calendar day)
Example 3: India Office Hours
Problem:Find overlapping business hours between New York (EST, 9 AM-5 PM) and Mumbai (IST, 9 AM-6 PM).
Solution:Mumbai IST = UTC+5:30\nNew York EST = UTC-5\nDifference: 10.5 hours\n\nMumbai 9 AM = New York 10:30 PM (previous day)\nNew York 9 AM = Mumbai 7:30 PM\n\nMumbai business hours in EST:\n9 AM IST = 10:30 PM EST (prev day)\n6 PM IST = 7:30 AM EST\n\nOverlap: None with standard hours
Result:No natural overlap - one side needs early/late hours