Get list of options for a given format type

Date Format String Definitions:
The defined date format must contain the day, month, and year format strings,
and a separator for the different units

• DD: 0 padded, 2 digit day number
• MM: 0 padded, 2 digit month number
• YYYY: 4 digit year format
  Date Separators:
• /
• -
• .