You can of course email them a screenshot of your calendar in month view, but if what you want is for them to have your events in their calendar, you would need to export your calendar, email them the ics file and they can then import it. However, this process does not allow for selection by date, so you would be sending them all events, past, present and future. You could of course edit the ics file before sending, to eliminate all events outside the time window.
You could take advantage of the fact that iCal will maintain multiple calendars for you. Make one called December, one January etc and put events for a month in the appropriately-named calendar, which you can then select for export and email. If you set the month calendars to auto-delete past events, then when you come to reuse a month it will only have one month's events in it.