Currently the only way to find the Parliament Calendar is calendar.parliament.uk.
Many MP staff members spend time copying the entries over to their MP's calendars manually.
This tool provides a subscribable calendar which updates daily with the latest published deadlines.
Anyone is welcome to use it - the code is all public so you can even check how it works.
With your calendar tool (probably Outlook), you can subscribe to these calendar urls:
To get setup, please follow the "Workaround" instructions here.
This tool was built over a weekend by attendees at the ToryTechs Hackathon