Confluence date picker cannot insert 30th & 31st March

Issue Summary

This is reproducible on Data Center: yes

Steps to Reproduce

1. Create a Space
2. Create a Page
3. Insert 31st March using date picker

Expected Results

The date on the Confluence page reflects the date you clicked.

Actual Results

31st March is inserted

Workaround

Click the lozenge again and select 31rd March