iCalendar.org Validator
icalendar.org/validator.html
What Jamie wrote
If you find yourself writing an ICS or iCalendar feed by hand this will come in handy to make sure it works right. This one seemed to detect timezone shenanigans well.
icalendar.org/validator.html
If you find yourself writing an ICS or iCalendar feed by hand this will come in handy to make sure it works right. This one seemed to detect timezone shenanigans well.