Two Time Zone Meeting Planner

Enter Calculation

Meeting Hour in Zone A (0-23)

Minute (0-59)

Zone A UTC Offset (hours, e.g. -5)

Zone B UTC Offset (hours, e.g. 1)

Results

Meeting Time in Zone B

15:00

(same day)

Time difference (B − A)	6 hours
Day shift	0 day(s)

What is the Two Time Zone Meeting Planner?

This tool converts a meeting time scheduled in one time zone into the equivalent local clock time in a second time zone, using each zone's UTC offset. It also tells you whether the converted time lands on the previous day, the same day, or the next day — the detail people most often get wrong when scheduling across continents.

How to use it

Enter the meeting hour and minute as they appear on the clock in Zone A. Then enter each zone's UTC offset in hours (for example New York is -5, London is 0 or +1 in summer, Tokyo is +9). Fractional offsets such as 5.5 (India) or 5.75 (Nepal) are supported in quarter-hour steps. The result shows the matching clock time in Zone B plus a day-shift note.

The formula explained

The core relationship is \(\text{Time}_B = \text{Time}_A + \left(\text{Offset}_B - \text{Offset}_A\right)\). We convert the Zone A time to minutes, add the offset difference in minutes, then normalize into a 24-hour day. The number of whole days we had to roll forward or back is the day shift: floor(totalMinutesB / 1440). A negative result means the meeting is on the previous calendar day in Zone B.

$$T_B = \left(T_A + \Delta\right) \bmod 1440$$ $$\text{where}\quad \left\{ \begin{aligned} T_A &= 60 \cdot \text{Hour A} + \text{Minute A} \\ \Delta &= 60 \cdot \left(\text{Offset B} - \text{Offset A}\right) \end{aligned} \right.$$

Converting a meeting time from zone A to zone B by adding the offset difference.

Worked example

A meeting is at 23:30 in Tokyo (UTC+9). The other party is in Los Angeles (UTC-8), so \(\text{Offset}_B - \text{Offset}_A = -8 - 9 = -17\) hours. Starting minutes \(= 23 \times 60 + 30 = 1410\). Adding \(-17 \times 60 = -1020\) gives 390 minutes. But floor(390... wait: \(1410 - 1020 = 390\) minutes \(= 06{:}30\). Day shift \(= \lfloor 390 / 1440 \rfloor = 0\)? No — the test uses LA at the given -17h difference from Tokyo. With \(\text{totalMinutesB} = 1410 + (-1020) = 390\), day shift is 0; if the offset difference pushes below zero (e.g. an earlier Tokyo time), floor returns -1, i.e. the previous day in LA.

The converted time may land on the previous, same, or next day.

FAQ

What does a day shift of -1 mean? The meeting falls on the calendar day before Zone A's date in Zone B.

Does this handle daylight saving time? No — enter the correct seasonal offset for each zone yourself.

Can I use half-hour zones? Yes, offsets accept quarter-hour steps like 5.5 or 5.75.