You can use grep
for this:
$ grep -Po '(?<=Job start time=).*' file
2014-03-13 06:37:49
$ grep -Po '(?<=Job end time=).*' file
2014-03-13 06:37:51
It used a look-behind that checks what comes after Job start/end time=
in the given file.
And to store into a variable, use
$ var=$(grep -Po '(?<=Job end time=).*' file)
$ echo "$var"
2014-03-13 06:37:51