The COVID-19 Metro Manila curfew from 2020-03-15 to 2020-04-14 (8pm to 5am) does not prevent travelers from going to the airport (Ninoy Aquino International Airport, MNL) during the curfew hours.
However, it has been announced on 2020-03-16 evening a total lockdown, which is supposed to 1) lead to the cancellation of all outbound international flights ...
Technically possible, but in practice very difficult unless you're a citizen.
While some international flights to/from the Philippines continue to operate, there have been massive capacity reductions, both to Manila and other destinations.
More importantly, the Philippines have also banned foreign visitors from countries with "local coronavirus ...
No: Duterte's lockdown on Metro Manila due to COVID-19 does not impact non-Filipino citizens traveling from Metro Manila to somewhere else.
I found the official reference: President Duterte's address to the nation on coronavirus actions on 2020-03-11.
The exact passage regarding air travel can be found at