mistake in calendar example

[Jack-Mutsers]

its not that important, since the purpose is to show how you can do it, but i noticed that in the calendar example that the days go on until in the 40s, while a month has at most 31 days. also i saw that the starting day is correct and that the fields before it are greyed out, but the end day goes to the end of the final (8th) row, instead of showing empty greyed out fields like those before the 1st day of the month.

[tonyqus]

https://github.com/nissl-lab/npoi-examples/issues/11 created

[tonyqus]

The bug is fixed!