I don't know if these are american, but what i find annoying when writing in English and online:
- 12 hour system instead of 24 hour system. 3PM and 3AM makes less sense to me than 15.00 and 03.00.
- Putting months before days in dates. 1.31.2020 makes less sense than 31.1.2020 to me.
I use both, but pm and am are just easier tho

It's just before and after noon, nothing too confusing lmao.
Interestingly enough, we use the AM/PM system more commonly despite being a British colony earlier and following the British spellings.
What if you have 1200547190
Isn't the rule to just place commas after every 3 digits from the right?
So it would be 1,200,547,190.
Although in India, we use the comma for 3 digits from the right, but after that for every 2 digits lmao. So in our country it would look like 1,20,05,47,190
