change month order

[Ar13f]

Please assist me; I'm trying to create a report similar to the one below, but the outcome isn't what I'm looking for:

I'm looking for the following result, I want the header for the month as below:

please help and advice, I have attached it to the workflow.

[Ar13f]

Dear @atcodedog05 

thank you very much for your advice and help ... it seems I really have to learn a lot in this community especially for regex functions (reply message from @cmcclellan) and formulas like this "DateTimeFormat(DateTimeParse([_CurrentField_],"%Y_%m_%d"),"%b-%Y")"

[atcodedog05]

Happy to help : ) @Ar13f 

Cheers and have a nice day!