I am looking to take a string as command parameter like HHMMSS and convert it to time format like HH:MM:SS and append it to current date (date needs to be generated within the script using 'date' command )
For example, if my command line argument will be 093500, this should be converted to 09:35:00 and be appended with current date like,
2018-05-16 09:35:00
Example:
$ ./convertTime.sh 093500
2018-05-16 09:35:00