Here's a slight improvement on Andres' implementation.
It still has the same restriction that 'seconds' must
have a ram address that is 0 mod 4 (e.g. 0x20, 0x24,...)

#define hours   FSR,1

        MOVLW   seconds
loop    MOVWF   FSR
        MOVF    INDF,W
        ADDLW   7
        SKPDC
         ADDLW  -6
        MOVWF   INDF

        ADDLW   0x100-0x60
        BTFSC   hours
         ADDLW  (0x100-0x24)-(0x100-0x60)
        SKPC
         RETURN

        MOVWF   INDF
        INCF    FSR,W
        BTFSC   hours
         RETURN

        goto    loop


17 Instructions, 3 RAM locations (or 4 if you count
FSR), and a restrictive location for the variables.
This has not been tested.

Scott