Mathematical Formula - Financial Calendar
Actual Day Basis
DYS = f(DT2) ‘“ f(DT1)
where:
f(DT) = 365 (yyyy) + 31 (mm ‘“ 1) + dd + INTG (z/4) ‘“ x
and
for mm d 2
x = 0
z = (yyyy) ‘“ 1
for mm > 2
x = INTG (0.4mm + 2.3)
z = (yyyy)
INTG = Integer portion.
Note: Additional tests are performed in order to ensure that the century (but not millennium) years are not considered leap years.
30/360 Day Basis
DAYS = f(DT2) ‘“ f(DT1)
where:
f(DT) = 360 (yyyy) + 30mm + z
for f(DT1)
if dd1 = 31 then z = 30
if dd1 ` 31 then z = dd1
for f(DT2)
if dd2 = 31 and dd1 = 30 or 31 then z = 30
if dd2 = 31 and dd1 < 30 then z = dd2
if dd2 < 31 then z = dd2