Date picker for Russian Language for month of "May"

Summary

Trying to choose date of month May using the Date Picker on Date Picket type Custom Field will prompt you a warning as the following:-

  Вы не ввели верную дату. Пожалуйста, введите дату в формате "d/MMM/yy", например. "17/фев/17"

Steps to Reproduce

1. Set profile language to Russian
2. Create issue and insert Due Date for May

Expected Results

Able to create the issue.

Actual Results

Error thrown and can't create issue.

Workaround

• Manually add the month name as мая instead of май