This is still a working in progress
Need to do Unit Tests and search for more use cases
Match partial cases of 8601 such as:
missing offset
missing time
only date and offset
nano present or not (and being from 1 digit to 9 digits)
Also properly captures the data by capturing only:
year, month, date, hour, minute, second, nano and offset (be it 'Z' or '+02:00' or' +0200')