DateTime formatting

[bauss via Digitalmars-d-learn]

I can't seem to find anything in Phobos that allows you to 
specify custom formats for dates.

Am I on my own or is there already such functionality?
I'm interested in a formatter with the possibility to output ex.:

December 20th, 2017 10:00 AM

All I could find was toSimpleString(), but it seem to use a 
pre-defined format like:
YYYY-Mon-DD HH:MM:SS