What this question isn't asking is how to add a new line below or above every line which matches a pattern.
What I'm trying to do is add a new line between a pattern that exists on one line.
Here is an example.
before:
Monday:8am-10pm
after:
Monday:
8am-10pm
Thus in this case, insert new line after every 'Monday' pattern.
Using sed:
will replace them (supposing you want 2 newlines as shown above)
For characters up to '
:
':