Square Root Day

Square Root Day is a holiday that occurs whenever the month and the day are both the square root of the last two digits of the year. The next Square Root Day will occur on May 5, 2025.

Dates
Square Root Day occurs nine times per century.

Millennial Square Root Days
The following dates have both the month and the day as the square root of the last three digits, rather than the last two, of the year, and could also be considered "Square Root Days":
 * Sunday, October 10, 2100
 * Tuesday, November 11, 2121
 * Saturday, December 12, 2144
 * Wednesday, October 10, 3100
 * Friday, November 11, 3121
 * Tuesday, December 12, 3144
 * Sunday, October 10, 4100
 * Tuesday, November 11, 4121
 * Saturday, December 12, 4144
 * Wednesday, October 10, 5100
 * Friday, November 11, 5121
 * Tuesday, December 12, 5144
 * Sunday, October 10, 6100
 * Tuesday, November 11, 6121
 * Saturday, December 12, 6144
 * Wednesday, October 10, 7100
 * Friday, November 11, 7121
 * Tuesday, December 12, 7144
 * Sunday, October 10, 8100
 * Tuesday, November 11, 8121
 * Saturday, December 12, 8144
 * Wednesday, October 10, 9100
 * Friday, November 11, 9121
 * Tuesday, December 12, 9144

The November 11 dates above coincide with Veterans Day.