The RealTime Clock (RTC) provides date and calendar functions and the ability to make program actions take place at certain times. It is documented here.
A quick summary of the range of values
| Item | Minimum | Maximum | Comment |
| Seconds | 0 | 59 | |
| Minutes | 0 | 59 | |
| Hours | 0 | 23 | 0 is midnight |
| DOW | 0 | 6 | 0 is Monday, 1 is Tuesday thru 6 is Sunday |
| Day | 1 | 31 | |
| Month | 1 | 12 | |
| Year | 0 | 99 | being 2000 thru 2099 |