Sony a (alpha) SLT-A55VL - Manual (Page 140)

140
Your camera maintains correct clock time by using GPS to acquire time
information during starting up. The time is corrected when the power is
turned off.
MENU button t 1 t [GPS Settings] t [GPS Auto Time Cor.]
t [On]
Notes
• [GPS Auto Time Cor.] is invalid if [GPS On/Off] is set to [Off].
• You must set [Date/Time Setup] on the camera before using it.
• There may be discrepancies of a few seconds.
• Depending on the area, it may not function correctly.
Correcting clock time automatically