Third-person singular simple present indicative form of calendar.(verb)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "calendars" in a sentence
"If you try to sign up, though, every individual class on the March and April calendars is listed as full, with no available seats."
"The Chinese calendar, like many other calendars, is lunar."
"We women seem to have plenty of time for doing things for others, but putting fun into our Blackberry or iPhone calendars is frequently a stumbling block."