Setting Date and Time
Setting date from the command prompt
To change the date on your Freerunner you have to give the command
date -s MMDDhhmm
date -s MMDDhhmmYYYY
date -s MMDDhhmmYYYY.ss
where MM is the month, 01-12; DD is the day, 01-31; hhmm is the time, 0000-2359; YYYY is the optional year, and .ss is the optional seconds.
If your Freerunner is connected to the internet, you can instead set the time automatically:
opkg install ntpclient ntpclient -s -h pool.ntp.org
Finally, sync the hardware clock with the system time to make your change persist over reboots:
See also Timezone for changing the time zone.
Presumably it might also be possible to use gpspipe (or something else) to set the date once you have a gps fix? In addition, the phone stack should set the date, time, and timezone once connected to a network.