hello jasper, i am facing the same problem. alarm doesnt work at all. i have made some changes in program and now clock and thermometer are working perfectly. clock is not much accurate but its fine. make the following changes in beginning.
replace:
sbit wr= P3^2;
sbit rd= P3^3;
sbit intr= P3^4;
with:
sbit wr= P3^3;
sbit rd= P3^4;
sbit intr= P3^5;
this helped me, as in the circuit 3rd, 4th and 5th pins are connected to wr, rd and intr respectively.
if clock is slow, you can make changes in j<1275, it worked for me.
PS: I am not a programmer but i made these changes and they worked for me however i am stll unable to get the alarm into work. please reply if you find any solution