From your own (unattributed) post.

" The attack, it said, was revenge for Turkish military involvement in Syria."

Therefore nothing to do with the calendar. And given that ISIS killed far more Muslims than others in the attack you can hardly claim it was directed at Christians. They simply attacked a secular, international holiday because was a time when the club would be packed with revellers. 

And for the last time, this has nothing to do with the issue of Muslim religious services in Peel Region schools. 

Oh and by the way...

"Prior to 1917, Turkey used the lunar Islamic calendar with the Hegira era for general purposes and the Julian calendar for fiscal purposes. "
https://en.m.wikipedia.org/wiki/Gregorian_calendar