how often do they update the amount of collected funds?
It really varies, unfortunately (^_^;). The patterns I've noticed are either weekly, every 10 days, middle of the month, or end of the month. So, I'd say it will probably be updated next either on the 10th, 13th, or 15th :). There's always a curve-ball chance of Meyaoi updating sooner, but those are my best guesses.