Calendar displays times in 12h format although it uses 24h format in other places (including calendar macro parameters)

[lucaa]

When displaying a calendar using the mocca calendar macro, the displayed calendar uses 12h time format (AM/PM) :

However, when editing the calendar macro, the day interval parameters (between when and when to display the calendar) are to be provided in 24h format:

Also, when events are created and displayed (see #51 ) , the times used are 24h based.

[lucaa]

Just as #51 , this ticket should be considered different from #44 , in the sense that even if the formats used by the calendar would not correspond to the ones on the wiki, it would still be better that they are coherent inside the application.

Another solution could be to still keep them incoherent but at least make the calendar use the format from the wiki, if any (that is, fix #44 but only for the time format used by the calendar display).