Calendar: vacations are confusing!

The situation:
I have 2 vacation days that will disappear March 8, 10 days that I can use any time before 2006 ends, and starting in June and ending September, we have flexible summer hours (ie. we can work an extra hour Monday-Thursday and then work a half day on Fridays or take Friday off every other weekend, or even bank those hours).

January
Friday, 13-Sunday 16: Arisia (2 vacation days)

February
Thursday, 16-Sunday, 20: AAAS conference in St. Louis, MO (1-2 vacation days)

March/April
Weekend of the 24th: Season of the Tree at House Gallae (? vacation days)
Friday, 31 - Sunday, April 2: Ad Astra

May
Friday, 26 - Monday, 28: Anime North

June
Friday, 16 - Sunday, 18: 9ICB AND Gaylaxicon
Saturday, 24 - Monday, 26: CSWA Annual Conference (0-1 vacation days)

July
Friday, 7 - Sunday, 9: Toronto Trek
Friday, 28 - Tuesday, August 1: Kaleidoscope Gathering (2-3 vacation days)

Sometime in September: NASW conference, but last time I was able to finagle these as "work from the hotel" days, so hopefully I could do that again.