Differentiate between Tokyo and Seoul Time zone

Question

both have the same Offset and not DST offset.

I am using java script to calculate the offsets. Also looked at parsing the string to get the name of time zone and it doesnt work so how do you differentiate between the two

Answer 1

if DST and Offset are the only info  and they are the same in both circumstances then you  wont be able to differentiate them You should not rely on Date's toString() or toTimeString(), they are specified to be implementation-dependent.
or you should try to  determine the user's geolocation (based on IP address) or provide the user with a list of regions / areas in his or her time zone to choose from