I added a free web calendar-compatible feed for the ARRL’s W1AW Regular Operating Schedule. Subscription link is:
Each entry has the expected frequencies and time of day that will, of course, be localized to your timezone.
I haven’t (yet) made any accommodations for holidays and such. It’s effectively exactly what’s on their Operating Schedule page placed in a calendaring-friendly format.
For more information about the W1AW’s operating schedule, please see this page.