List all times in the day at a half hour rate

Pyth, 26 bytes

Pjbm%"'%02d:%s0',"d*U24"03

Demonstration.

We start with the cartesian product of range(24) (U24) with the string "03".

Then, we map these values to the appropriate string formating substitution (m%"'%02d:%s0',"d).

Then, the resultant strings are joined on the newline character (jb).

Finally, we remove the trailing comma (P) and print.

Befunge-93, 63 bytes

0>"'",:2/:55+/.55+%.":",:2%3*v
 ^,+55,","<_@#-*86:+1,"'".0. <

 

^{(animation made with BefunExec)}

Bash: 58 47 46 characters

h=`echo \'{00..23}:{0,3}0\'`
echo "${h// /,
}"