2027 ColorCal This calendar spans October 2026 (USPS 2027 Q1) thru January 2028. Color and Alpha (A-F) Coded calendar for USPS Letter Carriers and Clerks using Sunday/Rotating Scheduled Day Off (SDO) calendar. NOTE: The SDO scheme depicts the schedule used by many districts and offices. Unfortunately, there are too many schemes to possibly address them all. As such, if your SDO colors do not match, find and use your matching SDO. The calendar displays Holidays, paydays and start of pay periods. It also has a grid of work weeks. There are NO nag screens. spam, pop-up or other annoying interruptions The app does not collect, save or ask for any personal information. Simple and clean interface. Disclaimer: This calendar is a personal project and not endorsed or sponsored by any organization. It is believed to be complete and correct.