with my hobby projects I use a 10k pot,1k safety resistor and 10k photo cell
you can add a little "debounce delay " for the headlights and cal with the pot

Code:
  LDR=1                         'POWER UP LIGHT SENSOR
 Pause 20 
 ADCIN 0,NIGHT                 'READ AN1 & STORE IN NIGHT VAR
  PAUSE 250
 IF NIGHT=<400 then  IT'S DAY SO DO THIS
  IT'S NIGHT SO DO THIS
 Pause 25                   
 
  LDR=0             'MAKE SURE LDR/ADCIN POWER IS OFF