Date time format

[Benality[3SFG]]

I am trying to format the date time on the personnel page.  

{datetime="$soldier->enlistment_date" dateonly="YES"}

I tried to modify that to 

{datetime="$soldier->enlistment_date->format('d F, Y')"}

Which does, in fact change the date, but it changes it to some random date that is not accurate.  Like Dec 31, 1969 or something. 

 

I would like the enlistment date to be displayed as 00 - Month - Year.