Imported Enum to define a CLI parameter with a predefined set of values to choose from. Created a spreadsheets_dir option and factory option.

Changed starttime/endtime to be defined by first absolutes reading starttime and last absolutes reading(last commit was supposed to include this but did not)

 Broke up code into smaller functions, changed starttime/endtime to be defined by first absolutes reading starttime and last absolutes reading endtime