Fast Day Fiasco
I am one of the more observant members on the board of a Jewish social organization, so a lot of Jewish ritual questions fall to me. We're planning a card party for later this summer, and I just realized that we inadvertantly scheduled it on Tisha B'Av. I feel responsible because I should have checked the calendar, and it's also completely non-negotiable to me that we change the date. Some other more secular members have said that since it's a "minor holiday," we don't need to reschedule. Our brochures are already printed, but we haven't sent them out yet. What do I do?
Fast Day Fiasco
There are some kinds of events (a lecture on a depressing topic, a screening of a sad movie) that you can get away with hosting on Tisha B'Av. But your instinct is correct that a party involving card games (especially if there's refreshments) is not on that very short list. Even if none of the other potential attendees plan to observe this most solemn day of mourning, it would still be inappropriate for a Jewish organization to host a social event on that date.
Last year I answered a question from someone trying to decide whether to fast on Tisha B'Av. I think struggling with that question is reasonable and valid. But as I said then, whether or not you observe the particulars behind the holiday, our tradition has decreed it to be a day of fasting and mourning. So your job now is to educate your fellow board members on why you really do need to change the date.
You can explain to them how seriously some communities observe this holiday. You can share some of the traditions behind abstaining from anything that could be pleasurable. You can provide evidence that no other Jewish organizations anywhere host social events on that day. Heck, you can even show them this column.
Be ready to propose alternate dates as well as a plan for changing any arrangements that have already been made. If necessary, offer to pick up some of the extra work that will surely go into rescheduling. Be gracious but firm, and I do think the rest of your board will come around.
As for the brochures, if possible, have new ones printed. It will be better overall for your organization to have a brochure free of any evidence of a scheduling snafu. If that's out of the question, try printing labels to put over the current date with the corrected date. If all else fails, you could change them by hand, though that seems like an awful lot of work as well as somewhat unprofessional. However, if that's what you have to do, recruit other members to help you and then mail them out feeling secure that you made the right decision. Perhaps this incident will propel your group to go to an online-only model of advertising with a monthly e-newsletter instead of printed brochures.
Finally, you want to make sure nothing like this happens again, so I highly recommend either using a daily planner that has the Jewish holidays pre-printed inside or, if you have a smartphone, adding a Jewish calendar to your calendar app. On my phone, I have Hebcal included in my Google calendar, and here are instructions for adding it yourself. You can customize it to show whatever you want: Shabbat candle lighting times, major holidays only, all holidays including minor fasts, weekly Torah portions, etc. You could probably even set it just to show Tisha B'Av, which, by the way, this year goes from sundown on Monday, August 4 until sundown on Tuesday, August 5.