Learn Hardcore Indonesian: Upacara bendera di sekolah kami dimulai pukul delapan pagi. - The flag ceremony at our school starts at eight in the morning.

Literally, upacara means ceremony and bendera means flag, so upacara bendera = flag ceremony.
In Indonesian, this is a common, almost fixed expression that usually refers to the formal flag-raising ceremony held at schools (often on Monday mornings), government offices, and on national holidays. When Indonesians hear upacara bendera, they typically picture that specific type of ceremony, not just any random event involving a flag.

What exactly does di sekolah kami mean, and how is kami different from kita or saya?

di = at / in / on (location preposition)
sekolah = school
kami = we / our (exclusive: the listener is not included)

So di sekolah kami = at our school (not including you).

Compare:

di sekolah kita = at our school (including you)
di sekolah saya = at my school (formal, polite)
di sekolahku = at my school (informal, using the suffix -ku)

Why do we say di sekolah kami, and what would change if we said upacara bendera sekolah kami without di?

Upacara bendera di sekolah kami focuses on the location: the flag ceremony that takes place at our school.
Upacara bendera sekolah kami makes sekolah kami modify upacara bendera, so it sounds like our school’s flag ceremony (a possessive relationship), not explicitly a location phrase.

Both can be grammatical, but:

With di, you are clearly talking about where the ceremony is held.
Without di, you’re talking about which ceremony (the one that belongs to our school), and the locative sense is only implied.

Is the word order Upacara bendera di sekolah kami dimulai... fixed, or can I move di sekolah kami to the beginning?

You can move it, but the nuance changes slightly.

Upacara bendera di sekolah kami dimulai pukul delapan pagi.
Neutral order: subject (Upacara bendera di sekolah kami) + verb (dimulai) + time.
Di sekolah kami, upacara bendera dimulai pukul delapan pagi.
Here, di sekolah kami is put first for emphasis: At our school, the flag ceremony starts at eight a.m. (implying it might be different elsewhere).

Both are correct; the original is the most typical neutral pattern.

What is the difference between mulai and dimulai in this sentence?

mulai = to start / begin (active voice)
dimulai = is started / is begun (passive voice, di-
- mulai)

In this sentence:

Upacara bendera di sekolah kami dimulai pukul delapan pagi.
= The flag ceremony at our school is started at eight in the morning.

You could also say:

Upacara bendera di sekolah kami mulai pukul delapan pagi.

In everyday usage, both are very common and usually understood the same; dimulai sounds slightly more formal or written, mulai more neutral/spoken.

Is the di in di sekolah the same as the di- in dimulai?

No, they are different:

di (separate word) = preposition meaning at / in / on.
- Example: di sekolah, di rumah, di Jakarta.
di- (attached to a verb) = passive prefix.
- Example: dimulai (is started), dibaca (is read), ditulis (is written).

They are written differently:

Preposition: di sekolah (two words)
Passive verb: dimulai (one word)

Writing di mulai (two words) to mean dimulai is considered a spelling mistake.

What does pukul mean here, and how is it different from jam?

Both pukul and jam are used when telling the clock time:

pukul literally means strike/hit, from the idea of a clock striking the hour. In modern usage, it functions like “o’clock”, and is slightly more formal or official.
- pukul delapan = eight o’clock.
jam means hour / o’clock, and is very common and neutral in everyday speech.
- jam delapan = eight o’clock.

In this sentence, you could say:

dimulai pukul delapan pagi (a bit more formal)
dimulai jam delapan pagi (very common in speech)

Both are correct.

Do I always need pukul or jam, or can I just say delapan pagi?

In natural Indonesian, when giving an exact clock time, you normally include pukul or jam:

pukul delapan pagi
jam delapan pagi

Just saying delapan pagi is understandable, but it sounds a bit incomplete or influenced by English “eight in the morning”. Indonesians will almost always say jam delapan or pukul delapan in full sentences.

How does pagi work here, and what are the other time-of-day words?

pagi means morning, and it follows the time:

Pattern: pukul/jam + number + time-of-day word
- pukul delapan pagi = 8 a.m.
- pukul dua siang = 2 p.m. (early afternoon)
- pukul lima sore = 5 p.m. (late afternoon)
- pukul delapan malam = 8 p.m. (night)

You can drop pagi/siang/sore/malam if the context is obvious, but when you need to make A.M./P.M. clear, you include it and place it after the number, just like in this sentence.

Can I add pada before pukul, like dimulai pada pukul delapan pagi? Is that more correct?

Yes, you can:

dimulai pukul delapan pagi
dimulai pada pukul delapan pagi

Both are grammatically correct. pada here is a preposition roughly like “at”, and adding it makes the sentence a bit more formal or explicit. In everyday speech and much writing, pada is often omitted and people simply say pukul/jam delapan pagi.

How do we know if this means “starts” (habitual), “started” (past), or “will start” (future)? There is no tense marking on dimulai.

Indonesian verbs (including dimulai) do not change form for tense. dimulai by itself is tenseless:

It can mean starts / is started (habitual/present),
started / was started (past), or
will start / will be started (future),

depending entirely on context or extra words, for example:

biasanya dimulai pukul delapan pagi = usually starts at eight a.m.
tadi dimulai pukul delapan pagi = earlier it started at eight a.m.
besok dimulai pukul delapan pagi = tomorrow it will start at eight a.m.

In a typical school-schedule context, the default reading is habitual: The flag ceremony at our school starts at eight in the morning.

How would this sentence sound in more casual, everyday spoken Indonesian?

A natural, slightly more casual version might be:

Upacara bendera di sekolah kami mulai jam delapan pagi.
(using mulai instead of dimulai, and jam instead of pukul)

Or even shorter if the context is clear:

Upacara bendera di sekolah kami jam delapan pagi.
(dropping mulai/dimulai; very conversational)

The original sentence is perfectly natural, just a bit more neutral/formal, suitable for written text or formal speech.

Does pukul delapan mean exactly 8:00, or can it mean “around eight”?

Literally, pukul delapan means eight o’clock, i.e., 8:00 sharp.

In real life, people might still be a bit flexible with time, but if you want to clearly say around eight, you usually add a word like:

sekitar pukul delapan = around eight o’clock
kira-kira jam delapan = roughly eight o’clock

So by itself, pukul delapan pagi is understood as a specific, exact time.