Why is the month value not changing after a CSV import with the correct date format?

Question

I am trying to import data from CSV which includes columns like task, start date, end date, status

CSV imported:

I was struggling with the date format during the import but once I believe I have sorted it to import without errors, I have noticed a logical error which changes only the day and year, but keeps the month as January by default, result is as below

Here is the date format used:

Jira

CSV

Any idea why this happens? Your help is highly appreciated!

Ismael Jimoh · Accepted Answer

I believe month should be MM not mm which is reserved for minutes.

I suggest opening the link for simplified dates to confirm this again.

The entry is case sensitive

unknown · Accepted Answer

I have matched the CSV date format with the Jira format similar to the one defined in the look and feel  Jira Settings -> System -> Look  and it worked properly