That seems like a terrible inconvenience to cause their customers without advance notice, I am a BPI customer and I did not get an email from them, thanks for posting it, I will email to a few friends who are in the Philippines now.
I will also add the actual schedule part of the message for those of you who may have slow connections.
http://philippineslifestyle.com/blog/2016/06/23/bpi-atm-online-banking-services-unavailable/The following is the schedule listed by The Bank of Philippine Islands:
Thursday, June 23:
1:00 am to 5:00 am ATMs, cash deposit machines (CDMs) and POS terminals
Friday, June 24:
1:00 am to 5:00 am ATMs, CDMs and POS terminals
1:00 am to 12:00 nn BPI ExpressLink
4:00 am to 10:00 am BPI Online Banking, Mobile app, Phone Banking and SIM Banking
4:00 am to 10:00 am Clients may experience intermittent availability of BPI credit, debit and prepaid card services
Sunday, June 26:
1:00 am to 5:00 am ATMs, cash deposit machines (CDMs) and POS terminals
1:00 am to 8:00 am BPI ExpressLink
4:00 am to 10:00 am BPI Online Banking, Mobile app, Phone Banking and SIM Banking
4:00 am to 10:00 am Clients may experience intermittent availability of BPI credit, debit and prepaid card services
Clients may still transact as usual in BPI branches and kiosks, and through their contact centers.
BPI enourages clients to plan ahead and complete transactions before the noted offline times posted.