All the time and calendar information is available in the time calendar (TC) dedicated registers: SECONDS_REG, MINUTES_REG, HOURS_REG, DAYS_REG, WEEKS_REG, MONTHS_REG, and YEARS_REG. The TC register values are written in BCD code.

• Year data ranges from 00 to 99.
  • Leap Year = Year divisible by four (2000, 2004, 2008, 2012, and so on)
  • Common Year = Other years
• Month data ranges from 01 to 12.
• Day value ranges:
  • 1 to 31 when months are 1, 3, 5, 7, 8, 10, 12
  • 1 to 30 when months are 4, 6, 9, 11
  • 1 to 29 when month is 2 and year is a leap year
  • 1 to 28 when month is 2 and year is a common year
• Weekday value ranges from 0 to 6.
• Hour value ranges from 0 to 23 in 24-hour mode and ranges from 1 to 12 in AM or PM mode.
• Minutes value ranges from 0 to 59.
• Seconds value ranges from 0 to 59.

Example: Time is 10H54M36S PM (PM_AM mode set), 2008 September 5; previous registers values are listed in Table 8-7:

The user can round to the closest minute, by setting the ROUND_30S register bit in the RTC_CTRL_REG register. TC values are set to the closest minute value at the next second. The ROUND_30S bit is automatically cleared when the rounding time is performed.

Example:

• If current time is 10H59M45S, round operation changes time to 11H00M00S
• If current time is 10H59M29S, round operation changes time to 10H59M00S