The Tapani calendar served as the timekeeping system within the Tapani sector for internal matters. Shey Tapani initiated this calendar in the local year 5,412, which corresponds to 7308 BBY. Although the Imperial calendar was employed for external galactic communications, the local Tapani calendar persisted as the standard for internal use, symbolizing the sector's independence. Minor adjustments were implemented to align it more closely with Galactic Standard Time, but the traditional names for months, days, and holidays specific to the sector were preserved.
The calendar's starting point, Year 0, is equivalent to 12,720 BBY, marking the arrival of the first colonizers in the region.