Stuck on porting code to 18F4520

[Scampy]

OK I've reverted to using a counter to dictate when each case statement is reached. The only issue i have is that for the life of me I can't work out how to slow the B_PWM=B_PWM+1 down so the PWM goes from 0 to 255 over the course of 30 minutes without stopping the clock running (such as would happen if a pause statement was used).

To make this simple I'm going to remove any user programming for now just to make things simple. If anyone can help with some code to assist me in achieving this delay between increasing / decreasing the PWM once every seven seconds without upsetting the clock it would be most appreciated. The timings in the code below are for testing only, so I'm not waiting for things to happen

If Counter1 < 1200 then
Blue_day_cycle = NIGHT
endif

if Counter1 = 1200 then
Blue_day_cycle = DAWN
endif

if counter1 =1202 then
Blue_day_cycle = DUSK
endif

  '*** Do BLUE daily cycle
    select case Blue_Day_Cycle
    case DAWN 
    lcdout $FE,$80+13,"DAWN "
            B_PWM = B_PWM+1
        if B_PWM = b_max then
            Blue_Day_Cycle = DAY
        endif
    case DAY
    lcdout $FE,$80+13,"DAY  "
            Blue_Day_Cycle = DUSK
    CASE DUSK
    lcdout $FE,$80+13,"DUSK "
        if  B_PWM > B_Min then
            B_PWM = B_PWM - 1
        endif
        if B_PWM = b_min then 
            Blue_Day_Cycle = NIGHT
        endif
    case NIGHT
    lcdout $FE,$80+13,"NIGHT"
        if HH = S2H and MM = S2M then
            Blue_Day_Cycle = DAWN
            b_cnt = 0
        endif 
    end select