# Need help figuring out how to calculate new calendar

#### magee101

##### New member
Hello there, I am creating a calendar for a sci-fi game I am creating for a roll20 session. I would appreicate some help in figuring out the current Month/Day/Year for this new calendar based on our Real World calendar date of 11/23/2645.

This new calendar is based on 11 months with 20 days (4 weeks of 5 days) with 23 hour days. It has no leap years. Year 1 of this new calendar is based on January 1st 2290 AD of our calendar. I would really appreciate some help figuring this out!

The main things I need help with is: Converting the extra hour per RL day into amount of days added to the new calendar. Figuring out where 2290 fits on the leap year schedule of our calendar to add in the extra day per 4 years.

The new calendar is a standard 220 23 hr days, as opposed to our 364/365 of 24hr days.

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#### Country Boy

##### Well-known member
MHB Math Helper
From 2290 to 2645 is 2645- 2290= 355 years. There are 88 leap years in the time so a total of 355(365)+ 88= 129,663 (earth) days and (129,663)(24)= 3,111,912 (earth) hours.

Now work backwards using the corresponding new planet values. An "hour" is not based on any planetary property (unlike the day or year) so I am going to take a (new planet) hour to be the same as an (earth) hour. Since there are 23 hours in a (new planet) day, 3,111,912 (earth) hours is 3,111,912/23= 135,300.522 (new planet) days and 12 hours). Since there are 20 days in a (new planet) month, that is 135300/20= 6765 months. Since there are 11 months in a (new planet) year, there are 6765/11= 615 years. So, taking 2290, on earth, as the "zero" year for this new planet, 2645 is 615 years, and 12 hours. That would be a little before noon of Jan 1, 615 on this new planet.

#### magee101

##### New member
Thank you so much! Also taught me how to work through similar problems later