I believe right after Halloween
Not sure about end but starts November 9. Guessing it'll be over 1/1/19 https://disneyland.disney.go.com/events-tours/holidays-at-the-disneyland-resort/
Nov 9, 2018 - Jan 6, 2019
I think you might want to check out the Disneyland site for the answer to this question. I would also suggest you install the official Disneyland app, to your phone, which provides comprehensive information regarding events, schedules etc.
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