The expiration date is a date that
applies to per diem rates. It is important because it shows the last date
that CONUS or
OCONUS
per diem rates are valid. When a pilot or flight
attendant uses EZPERDIEM.COM
Per Diem Calculator
TM, the
effective date, the expiration date, the
seasonal start date, and the
seasonal
end date are all checked against the date of each layover that gets entered.
The per diem rate tables are not
always standardized, so EZPERDIEM.COM uses a complicated algorithm to extract
that data straight from the government provided per diem tables.
Often, the expiration date for per
diem rates occurs on October 1st. That date marks a time called the
transition period, which is the last three months of a calendar year. Simply using that year's per diem rates for the remainder of the tax year
based on seasonal start and end dates is a way of handling the issue with the
transition period when the per diem rates for the following year are not
available.