if(Serial1.available() > 0){
h = Serial1.read();
m=Serial1.read();
If there is at least one byte of serial data available, it is NOT okay to read two bytes.
if(Serial1.available() > 0){
h = Serial1.read();
m=Serial1.read();
If there is at least one byte of serial data available, it is NOT okay to read two bytes.