Not tested but assuming you're not using any Gosubs... it could work.

Inspiration taken bellow
http://www.picbasic.co.uk/forum/show...light=modifier

Sure it could be dangerous.... compile O.K
Code:
@ device pic10F202, mclr_off, protect_off, wdt_off

TRISIO = %1100

asm
dim=SOFT_STACK  		
Time=SOFT_STACK + 2
Time2=SOFT_STACK_PTR
endasm
dim   VAR WORD ext
Time  VAR WORD ext   
Time2 VAR BYTE ext
b0    VAR BYTE 

Clear
GPIO = 0
dim = 100


Start:
    time = time + 1 'increment timer in 1/50 seconds
    
    IF time > 30000 Then 'make a 10 min increment
        time = 0
        time2 = time2 + 1
        EndIF
    
    b0 = b0 + 1 'increment for every 4 phase cycles
    IF b0 >= 3 Then b0 = 0
    
    IF (time2 >= 2) then 
       if b0 = 2 Then dim = dim + 1 'if over 20 min then start dimming dim period 4 cycles = 10 mins
       endif

    IF dim > 7500 Then dim = 7500 'down to dim level - 9000 = off, 7500 approx 15%
    
    if time2 > 72 then 'turn off after 12 hours
        dim = 9000
        time2 = 73 'prevent from cycling
        endif

LowSide: 'look for GPIO.3 points and GPIO.3 GPIO.2
    IF GPIO.3 = 1 Then lowside 'wait for phase to go low
    GPIO.5 = 0 'weight input to sense zero crossing
    PauseUs dim 'wait for dim period
    TRISIO.2=0 'fire GPIO.2
    GPIO.2 = 0
    PauseUs 400
    TRISIO.2=1

HighSide:
    IF GPIO.3 = 0 Then HighSide
    GPIO.5 = 1
    PauseUs dim
    TRISIO.2=0
    GPIO.2 = 0
    PauseUs 400
    TRISIO.2=1
    GoTo start
Good luck!