I got my first dreaded date of "December 21, 1969", this morning. I have several different backups, so it wasn't a big deal, but it's worth looking into the code to figure out what happened.
About the phone: Running UD8.0 with 3 wipes of data and cache (SPRecovery install). Running 928 Droid theme over the top of it (no wipes - not that much of a noob, standard overlay install via SPR) with Slayher 1100 LV kernal (can't remember if I installed via SPR or CM, I often use CM for simple installs like kernels).
What I did: I installed the Cytown Phone App in the Modified App section of UD Settings. I decided I didn't like it as much as the 928 themed phone, so I tried to flash back to the Stock Phone right above the Cytown App in UD Settings and it threw me into a bootloop of force closes. I pulled the battery to stop the loop and when I rebooted after putting the battery in, it gave me "the date." I simply flashed back to my clean UD SPRecovery backup and all is well, but thought y'all should know how it happened. If I didn't include something relevant, let me know and I'll add more info...