A RBC model code problem about the dynamic equation of K

I have the dynamic equation of K and the budget equation :
f3
I see a book of the code is :
k=exp(z)k(-1)^alphalab^(1-alpha)-c+(1-delta)*k(-1);
why the period of lab and c in the code is t ?,I think is (t-1) because
the equation of K is:
k=exp(z)k(-1)^alphalab(-1)^(1-alpha)-c(-1)+(1-delta)*k(-1);

Capital here is a predetermined variable. Given Dynare’s stock as the end of a period notation, you need to shift your equations in stock at the beginning of period notation by 1 period to the past.

I understand ,thank you jpfeifer