To keep costs low, the Raspberry Pi does not include a Real Time Clock module. Instead,
users are expected to have it always connected to WiFi or Ethernet and keep time by checking the network.
To have correct time:
In Raspup set the time to use a time server to give correct time setting.
menu->Desktop->Psync Time Server Synchronization
Best to pick a time server near your location on the earth.
Set the correct time zone by using the menu->Desktop->Set Timezone
With correct time zone selected and time provided by a time server.
The Pi computer should be displaying correct time when using Raspup OS.
When it first boots to desktop.
It may take a little time to set the correct time.
My Pi 400, usually takes 10 to 15 seconds, after it gets to working desktop.
Check the date time, on right side of the desktop tray, to see if it corrected to the correct time.