The days
hari Senin ‘Monday’
hari Selasa ‘Tuesday’
hari Rabu ‘Wednesday’
hari Kamis ‘Thursday’
hari Jumat ‘Friday’
hari Sabtu ‘Saturday’
hari Minggu ‘Sunday’
The word hari ‘day’ usually comes in front, though it is dropped in casual speech. Most of these come from Arabic, which is why they resemble nothing in English.
Jumat is worth noting: it is Friday prayers, and in much of Indonesia the working day is shorter because of it.
The Minggu problem
Minggu means both Sunday and week.
hari Minggu ‘Sunday’
seminggu ‘one week’
minggu depan ‘next week’
Capital M for the day, lower case for the week, but nobody is consistent in writing and speech has no capitals at all. Context does the work.
The months
Januari, Februari, Maret, April, Mei, Juni, Juli, Agustus, September, Oktober, November, Desember
Borrowed and near-identical to English. This is the cheapest vocabulary in the language.
Dates
Indonesian puts the day first, then the month, then the year. No ordinal numbers, no of.
tanggal tujuh belas Agustus ‘17 August’
17 Agustus 1945 the independence date, and one every Indonesian knows.
Asking:
Tanggal berapa hari ini? ‘What’s the date today?’
Note berapa ‘how much’ again, doing the same job it does with prices and with the time.
Putting a day and a date together
hari Senin, tanggal lima Mei ‘Monday the fifth of May’
The day comes before the date, which is the reverse of the usual English order.