[...]
timer2  = (TH2 - TIMER2_HIGH) << 8;
timer2 |= (TL2 - TIMER2_LOW);
time = 500000 * numHalfSec + 8 * timer2;
[...]

[...]
timer2  = TH2 << 8;
timer2 |= TL2;
time = 500000 * numHalfSec + 8 * (timer2 - TIMER2);
[...]