check format of date with moment.js

if it's just for checking the below is a better alternative

moment(scope.modelValue, 'DD-MMM-YYYY HH:mm a', true).isValid()

For checking date format you could use:

moment(checked_date, DATE_FORMAT).format(DATE_FORMAT) === checked_date

If you don't have a particular date format then you can also use Array of formats,

moment(checked_date, [DATE_FORMAT1, DATE_FORMAT2]).format(DATE_FORMAT)
 === checked_date