Uniform Month Calendar Converter

Convert from Gregorian dates to 13-Month Calendar dates

Enter a Gregorian Calendar Date

13-Month Calendar

WWW, month d, yyyy

Gregorian Calendar

WWW mmm dd yyyy

Uniform Month Calendar Date Readouts

Uniform Date Year Month Day Weekday Day of Year Week #
Unknown 1900 12 (February) 23 Friday 331 331
Gregorian Date Leap Year Days Lost on Adoption Leap Day (if LY) New Month Names
Unknown No 1900 12 (February) 23

Uniform Month Calendar Settings

* = Preferred Selection

New Calendar Starts On:
Leap Day Added:
Name of the Free Day at the end of year:
Names of the New Calendar Months:

2016-2020 CE to Uniform Month

1582 CE Gregorian Calendar Adopted
46 BCE the Julian Year Adopted

Old Date String UY Day New Date String

Gormanian, what's that?

The Gormanian calendar is an idea from Series 3 Episode 7 of Dave Gorman's "Modern Life is Goodish" show. We know how many seconds are in a minute, how many minutes are in an hour, how many hours are in a day, how many days there are in a week, how many months there are in a year, but we don't know how many days or weeks there are in a month! It changes each month. The 13-month calendar solves this issue by making each month 28 days long, as well as by adding another month and an intermission. This calendar also renames and moves some months. (e.g. OCTober should be the 8th month, not the 10th)