How can I enter 1968 as a resource‘s date of birth in the date field when the calendar control only begins at 1972?

To select a date earlier than the earliest date on the year drop-down list, select the earliest date possible for the year on the calendar control so that PPO accepts that date.

Then reselect the year drop-down again. PPO will then display the previous 50 years for you.

By default only the last 50 years are shown when the calendar control is first loaded.