Answer:
Time Zones not only depend on Geographical locations but also on political phenomenon like countries area more on East-West or on North-South.
Actually standard way of writing time zone is in 24 hour format and so 8:10 pm should be written as 2010 hours.
Generally if you are interested in calculation only than should not write in the question as standard time the question further have other complications like International Date Line crosses for that 24 hours cycle comes in to play.
For this reason International Date Line is crooked imaginary line as this must not touch any portion of the land, island, peninsula.
Step-by-step explanation: