Need update to formula

[bam12]

=IF(C4="","",IF(C3="parttime",0,LOOKUP(DATEDIF(C4,TODAY(),"m"),{0,3,96,180;0,10,15,20})))

I have this formula the second part works but they first part has changed

If you are a part timer you only get 4 days vacation after a year there before they didn't get any

c4 is the the start date
if full time the formula works great,

Hope someone can help me update this formula for part timers thanks in advance for any help

 

[Dave Patton]

=IF(C4="","",IF(C3="parttime",IF(TODAY()-C4>365,4,0),LOOKUP(DATEDIF(C4,TODAY(),"m"),{0,3,96,180;0,10,15,20})))