Generate calendar

Lay out one Gregorian month as a Sunday-first monospaced weekday grid.

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ToolCalendar Generator
Input
Output
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Preview

How it works

The first UTC date supplies the leading weekday offset, Gregorian month length bounds the numbered cells, and each day occupies a fixed three-character column. UTC construction explicitly preserves years 0001–0099 instead of JavaScript’s legacy 1900 shift.

  • The current browser month and year are initial values for an immediately useful wall-calendar view.
  • Sunday-first ordering is this display’s convention; ISO weeks begin on Monday.

Worked example

January 2025 Calendar
Generate a text calendar for January 2025
Input
											Month: 1
Year: 2025
Output
												    January 2025
Su Mo Tu We Th Fr Sa
          1  2  3  4
 5  6  7  8  9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31

When to use this

Terminal notes use monospaced calendars, printable plans need weekday positions, and fixtures verify the first weekday of a month.

Edge cases

  • February 1900 has 28 days because a century year must also divide by 400, while February 2000 has 29.
  • A Saturday start inserts six empty weekday cells before day 1.
  • Year 0001 stays year 1 rather than silently becoming 1901.

References