To make a Calendar event that repeats the 1st, 3rd, and 5th weeks, just select the '1st, 3rd, and 5th weekends' option in the 'Add Calendar Event' screen under 'Repeating Options'.
The Calendar will automatically mark Friday, Saturday, and Sunday every 1st, 3rd, and 5th weeks. If you start the event on a Wednesday, the Calendar will begin on the next weekend that matches the 1st, 3rd, and 5th weekend pattern.