It will come as no surprise to anyone who knows the slightest bit about the Philippines and Filipinos that this is a very religious country, with the vast majority (82.9%, according to the CIA Factbook) being Roman Catholic. (Only 0.1% have no religion).
Therefore it will not surprise anyone that Holy Week is taken rather more seriously here than it is in the US.
To the extent that Holy Week is celebrated in the US, only Easter Sunday is really observed, with some attention to Good Friday. Many people go to church on Easter Sunday who don't go otherwise, and a great many families have special dinners. Otherwise it's all about the Easter Bunny. Some, not many, go to special services on Good Friday. Even for the religiously inclined, that's about it.
Few businesses close at all -- those that close on Easter Sunday are those that close all Sundays. The limit of Good Friday observance is that many businesses (most that I worked at) will allow those few employees who request it to take Good Friday off without any penalty (other than using up a vacation or sick day).
It's rather different here, and not just in the fact that Holy Week is widely observed -- one would expect that a deeply religious society would be more public in its observance than a mostly secular one -- but also that the emphasis in terms of which days matter is different.
I got my first clue when I saw a sign on a mall store saying, "We will be closed on Maundy Thursday and Good Friday." Friday didn't surprise me much, but Thursday?
Then I found out that that was not at all uncommon here. The laundry where I take my clothes is closed on Thursday and Friday, but open Saturday and Sunday. My gym, which is normally closed Sunday, is closed all four days (I'm assuming the guy who runs it is taking advantage of an opportunity for a four day holiday, beside seeing no point in closing two days, opening one, then closing again). Almost all businesses that are normally open Sundays will be open Easter Sunday, but most are closed Thursday and Friday.
An exception that perhaps makes my point: the most popular expat place in my neighborhood (Marshall's Irish Pub), which is owned and run by an American, has a sign out front saying, "We will be open every day during Holy Week."
I still haven't figured out why Maundy Thursday is considered a big enough deal to justify closing, when Easter Sunday isn't.
Nor have a figured out why Filipinos call it Maundy Thursday. In my experience, it is almost always Holy Thursday, and the occasional uses of Maundy are from Protestants. Just another couple Philippine mysteries, I guess.
Bonus oddity: The day after Good Friday is 'Black Saturday' here.