Converts a time from one region to another. Each region is given as its UTC offset — 9 for Japan, 5.5 for India. Where daylight saving applies, enter the offset in force at the time.
This tool converts a time from one region to another, which is what a meeting across borders or an arrival time comes down to.
Here is the original time in minutes, the UTC offset of the source region, that of the target and the converted time. Every local time in the world is defined as an offset from UTC, so converting between two of them means removing one offset and applying the other.
If comes out below zero the result falls on the previous day; if it reaches 1440 or more it falls on the next. Converting from Japan to the Americas almost always moves back a day.
09:00 in a region at UTC+9 becomes 19:00 on the previous day in a region at UTC−5, a difference of 14 hours.
09:00 is 540 minutes. The difference in offsets is −5 − 9 = −14 hours, or −840 minutes, so 540 − 840 = −300. Being negative, it wraps to the previous day: adding 1440 gives 1140 minutes, which is 19:00.
Offsets are not always whole hours. India is at +5.5, Nepal at +5.75 and central Australia at +9.5, so decimals are accepted as they stand.
Where daylight saving is observed, the offset itself changes with the season. That is why this tool takes an offset rather than a list of cities: a built-in list would quietly be an hour out for half the year. New York is at −5 in winter and −4 in summer, so enter whichever is in force on the date in question.