A calendar is a system of organizing and measuring time. It can be used to track events, appointments, and deadlines, and can be in the form of a physical book or a digital application. Calendars can be based on different systems, such as the solar year, lunar month, or a combination of both. Some popular calendar systems include the Gregorian calendar, which is widely used in the Western world, and the Islamic calendar RED EMBER Guinea Pigs 2023 Hangable Monthly Wall Calendar | 12" x 24" Open | Thick & Sturdy Paper | Giftable | Kids Animals Brighten Your Day The calendar for 2023 has 365 days, with 52 weeks and 1 extra day (leap year). It begins on Sunday, January 1st and ends on Monday, December 31st. Some notable holidays in 2023 include: -New Year's Day (January 1st) -Martin Luther King Jr. Day (January 16th) -Valentine's Day (February 14th) -President's Day (February 20th) -Easter Sunday (April 16th) -Mother's Day (May 14th) -Memorial Day (May 29t...