four days from now; five days from now (regional)
Refers to the day four days after today in standard usage, but in some regions it means five days from now. Used both as a noun and adverbially.
Four days from now is my friend's birthday.
Depending on the region, 五明後日 can refer to five days from now.
Means 'the day after tomorrow' (two days from now), while 五明後日 is four (or five) days from now.
Means 'three days from now', one day closer than 五明後日.
Formed from 五 and 明後日 as a calendrical sequence name. Its reference varies regionally because traditional counting may include or exclude the present day.