Timing limiter for execution of commands in Bash/Shell Script

I have a shell script which looks like this:

echo firstOutput
read -s
command0
command1a
command1b
command1c
echo secondOutput
command2

command1a, command1b, command1c are individual commands but they can be executed in arbitrary order and are a group in the sense of the following explanation.

I now want to improve it so the script continues even if one command gets stuck. command0 needs to be executed first and it got 8 seconds to operate. If it doesn't make it within 8 seconds, the script shall continue to command1[a-c] which together have 5 seconds to operate. If they don't terminate within the given 5 seconds, command2 shall be called. Just in case this matters: command2 is the last command of this script.

Edit: To clarify: I know how to make a script which executes the commands in the maximum time allowed. However, these are timeouts and I want the script to run through as fast as possible. The entire script usually runs through in a fraction of a second after enter is pressed (see line read -s).