Understanding the Gregorian Calendar
Days, weeks, months, and leap years — the system that organizes our year
45 minFoundations
Learning Objectives
- Identify and name the seven days of the week and the twelve months of the year
- Demonstrate familiarity with days and months and apply calendar skills to real tasks
- Understand the origin and history of the Gregorian calendar and its relation to the solar year
- Understand the concept of leap years and how they affect the calendar
The Knuckle Trick
Make two fists and line them up. Starting with January on your left pinky knuckle, alternate between knuckles (peaks = 31 days) and valleys (30 days, except February). Knuckle months: Jan (31), March (31), May (31), July (31), Aug (31), Oct (31), Dec (31). Valley months: Feb (28/29), Apr (30), Jun (30), Sep (30), Nov (30). When you reach the knuckle of your left index finger (July), jump to the knuckle of your right index finger (August) — both are 31 days.
Quick Check
1. Which months have exactly 30 days?
2. Is the year 1900 a leap year?
3. Write the date "December 5, 2026" in the format YYYY-MM-DD.