You can use RTE = FNNESB where NN is your date type in 0041. The documentation from SAP is shown below. Hope this helps.
F Fixed indicator for deadline calculation
aa Date type: Start date of period to be
calculated; if the date type is not 'nn,'
the second position is left blank.
e Unit, in which the duration is calculated:
T = days
W = week
M = months
C = complete months
K = complete calendar months
N = complete calendar months (rounded up)
J = Years
Y = Complete years
The difference between the individual
units is explained in
Calculation Examples
in more detail.
s End date of period to be calculated:
(blank) End of current payroll period
J End of current calendar year
A Start of current calendar year
B Start of WPBP period
No other specifications are possible.
b If the date type specified in parameter aa
does not exist for the person in question,
Based on the return value you can do your calculations.
Regards
Pramod