Don't know if it's really "better", but you can use:
Ceiling ( Position ( "JanFebMarAprMayJunJulAugSepOctNovDec" ; Left ( Status Month Name ; 3 ) ; 1 ; 1 ) / 3 )
Well, it's definitely shorter. :-)
And since your data is already using 3 letter abbreviations for the month name, you can make it even shorter by removing the left function.
Bench test on MacBookPro, OS 10.7.5, 2GHz Intel core i7, FMP12v4, and 100,000 SetField loop...
Phil's clever use of Ceiling for the divisor of "3", using the nearest Second of time and Month of "Jan" 11 Seconds
Phil's with Monthe of "Dec" also 11 Seconds
Eric's Case Statement Month "Jan" 13 seconds
Reason is that FMP is an Interpreter and the shorter the calculation, the faster.
Neither solution has error checking or default.
Military dates are in similar format. 04JUL2013
I gave Phil a "I like it" mark for use of Ceiling and its opposite is Floor...
PS: Just for fun...