Time Zone Fixer is a good program. You want to save your default P3D flight in an airport near your location then when starting it you check the use UTC box before selecting another airport in the menu. Now you load into the sim, wait a minute for everything to load, and go up to the menu and select the right UTC time again. (make sure the date its right for UTC). Before this double check your P3D options have "use system time" checked.

Doing this you do not have a need for FS Real Time unless you want to make sure after long flights your clock does not get too far behind. Using my steps above you should not be more than 2-3 minutes behind after a long flight thanks to pauses in P3D that we cannot get rid of. FS Real Time includes some time zone bgl files but Time Zone Fixer is more up to date.

Edited August 18, 20196 yr by Boeing or not going

I have Time Zone Fixer but have no need for FS Real Time. For example, If I'm going to fly Concorde from Honolulu to LAX I want to fly it in daytime. Now PHNL is 11 hours behind UK time so if I had FSRT it would keep fighting me to get the time correct for my flight. I really don't fancy pushing back at 21:00 UK time for a 10:00 local departure. Much rather depart at 10:00 UK time and have control over P3D time.

I keep the time difference sync'd with FSUIPC5.