((a)) ** Officers first becoming members before ** Each officer on the retired list who first became a member of a uniformed service before , shall receive retired pay at the rate determined by multiplying—
((1)) the retired pay base determined under ; by
((2)) the retired pay multiplier determined under section 1409 of such title for the number of years of service that may be credited to the officer under section 1405 of such title as if the officer’s service were service as a member of the Armed Forces.
((b)) ** Officers first becoming members on or after ** Each officer on the retired list who first became a member of a uniformed service on or after , shall receive retired pay at the rate determined by multiplying—
((1)) the retired pay base determined under ; by
((2)) the retired pay multiplier determined under section 1409 of such title for the number of years of service that may be credited to the officer under section 1405 of such title as if the officer’s service were service as a member of the Armed Forces.
((c)) ** Treatment of full and fractional parts of months in computing years of service**
((1)) ** In general** In computing the number of years of service of an officer for the purposes of subsection (a)—
((A)) each full month of service that is in addition to the number of full years of service creditable to the officer shall be credited as ⁄ of a year; and
((B)) any remaining fractional part of a month shall be disregarded.
((2)) ** Rounding** Retired pay computed under this section, if not a multiple of $1, shall be rounded to the next lower multiple of $1.