Auo enter creation date and time are user's computer date and time.
For a good result in multiuser application it would be better to use the host timestamp, by a script with Get(CurrentHostTimeStamp)
filemaker_mmfg - Is a script necessary, or can you simply use an auto-enter calc with Get(CurrentHostTimeStamp)?
But in general, yes auto-enter date/time/timestamp are on the client machine, so whenever possible I use the "Host" version of time, just to keep things consistent.
I don't have any experience with systems large enough to have users in multiple time zones, so I'm not sure what issues you would run into with that.
The advantage of the script is that it can be triggered as you need, i.e. when you create the record or when you commit it, so the consistency can be driven based on what you need. This is specially useful when many people create many records in the same time.
I use a custom function in an auto-enter calc. That custom function can do a few things, but I start off with Get ( CurrentHostTimestamp). Then if it's the host is in a different timezone than all the users, I can adjust the function to match local time. If it's a "multi-user in different time zone situation" then I can adjust the custom function to meet the business needs.
For modification timestamps, I use a calc that that references the modification account name field with the same custom function.