ColorCal 2021 Postal Color and Alpha (A-F) Coded calendar for Postal Letter Carriers and Clerks using USPS Sunday/Rotating Scheduled Day Off (SDO) calendar This calendar spans October 2020 (USPS 2021 Q1 ) thru January 2022 (USPS 2022 Q1) Note taking has been integrated into this version and the previous note taking versions have been eliminated NOTE: The SDO scheme depicted in this calendar, matches commonly available printed calendars. For security, there is no online calendar integration. It