This variable contains the date when the individual first began receiving retirement
benefits and is stored as a SAS date variable. Benefits always begin on the first
day of the month. Individuals born before 1920 were eligible to receive their first
payment in the month they turned 62 unless their birthday was the first day of the
month, in which case they were eligible for their first payment the month before they
turned 62. Individuals born on January 1 were eligible to receive their first payment
in the December before they turned 62. Individuals born in 1920 or after were eligible
to receive their first payment the month after they turned 62 unless their birthday
was the first or second day of the month, in which case they were eligible for their
first payment in the month they turned 62.