byDay accepting iCal format, e.g. "2TH" #162
Description
As mentioned in schemaorg/schemaorg#1457 (comment), the original discussion around this proposal in schema.org seemed to include consensus for byDay accepting iCal format, e.g. "2TH".
This must be included for iCal compatibility and to allow existing implementations like Bookwhen to accurately represent their schedules.
More info / examples linked from here: #2 (comment)