Apparently that is a demo template not intended for distribution. Vendors will mock up text in Latin so prospective clients can get a feel for how their product or service will appear. They don't want you getting down in the weeds of the verbiage (which will be drafted to your specifications later), just a visual impression. Hence the Latin.
The upside... you can use that calendar again in 2032, the next time a leap year begins on a Thursday.