Honeywell Server and Station Timing Synchronization Issue

I need assistance for the following issue:

I work in a company where we have Honeywell DCS System with 4 C300 Controllers. We have 2 Servers and 6 Console Stations. The problem is that the Server and Console Station time is not synchronized with our local clock time. I mean let say in Pakistan the current time is 5:00 PM but the Honeywell Server and Station timing is around 1 hour and 30 minutes back which means that it will be showing time 3:30 PM. This difference in timings made it difficult for us to analyse trends, alarms, event summary to exactly find out what actually the time was in clock. We have to refer DCS time always and add 1 hour & 30 minutes to evaluate that this was the exact time at that instant. Please help me out to synchronize this timing issue.

I want to exactly know that:

1- Can this be changed in running chemical plant?

2- From where to change time which can instantly change all stations and Server time at the same moment?

3- How will controller behave after this? Will there be any abnormal situation?

4- What will be the effect of timing change on the DCS event and trends log?

Please guide me in resolving this very critical issue