Sony confirmed that there was an error and stated that they were narrowing down the issue and were continuing to work to restore service. By March 2 (UTC), 2010, owners of original PS3 models could connect to PSN successfully and the clock no longer showed December 31, 1999. Sony stated that the affected models incorrectly identified 2010 as a leap year, because of a bug in the BCD method of storing the date. However, for some users, the hardware's <answer>operating system clock</answer> (mainly updated from the internet and not associated with the internal clock) needed to be updated manually or by re-syncing it via the internet.
What clock unrelated to the error in the PS3 had to be updated in some cases in order to fix the bug?
operating system clock