Issue Summary

When the change calendar has a high amount of changes to list it shows the error  "We're having trouble loading the calendar".

Views of type List and Month are affected. 

Week and Day views are less affected as they show fewer issues. 

Steps to Reproduce

1. Create a good amount of change issues (e.g. 2 thousand), with fields "Planned Start, "Planned End" and Change Reason filled, where the planned start should be in the same month for all created issues.
2. Access the Change Calendar for the related month.
3. Change the view from Week to Month or List.

Expected Results

The change calendar shows all change issues.

Actual Results

The error "We're having trouble loading the calendar" is shown or the page becomes unresponsive.

Workaround

Using filters (project, status, etc) may help.