No that this isn't a bug report against calendar (which is prototype I know) but against bad javelin component.
However the step to reproduce use calendar since it's is the most obvious part where this javelin component is used.
Step to reproduce
- set Week Starts On to monday in user pref (who starts the weeks on sunday anyway)
- create a new calendar event
- try to fix end date going to something in november 2015:
- to do this use arrows
- then it freezes chrome windows
My understanding
Debugging it in chrome reveal me that when trying to edit the month and go to the next month :
I'm note sure how to fix this @epriestley, would you mind guide me ?