:

Our custom field documentation has descriptions of all the codes that can be used in the date formats.
Be careful, the date formats are case sensitive and you must use capital M when when configuring months. Common examples are :

Date and Time Pattern Result
"yyyy.MM.dd G 'at' HH:mm:ss z" 2001.07.04 AD at 12:08:56 PDT
"EEE, d MMM yyyy HH:mm:ss Z" Wed, 4 Jul 2001 12:08:56 -0700
"yyMMddHHmmssZ" 010704120856-0700