The meaning seemed obvious from the context. I thought he was going to rearrange a schedule. I've just checked online for a definition and found calendarize at Urban Dictionary:
1. calendarizeGiven that the speaker had an Australian accent, I would prefer to find calendarise, but I've had no luck with that one. Writers Events did have a definition, but it wasn't of the sense in which I heard it used in the library.
To add a scheduled event to a planning calendar, so that it may serve as a future reminder.
A friend invited me a to a party he is holding in a few weeks. I calendarized it so that I would not forget.
2. calendarize
(V): The action of placing an event or occurrence onto a calendar.
I need to calendarize my dentist appointment.
1. accounting.My first reaction was that it's a horrible word, and that he could have simply used reschedule. On second thoughts, however, I'd have to say that recalendarise has a slightly different tone to it, because it gives me an impression of modern technologies in action. When I heard it I assumed he was going to do something on a computer. Also, schedule doesn't have the extra meaning of noting the date on a calendar.
To divide (eg a budget) into equal units of time, usually months, within a year.
Etymology: 20c.