This is the 155th most frequent Slovenian word.
petek
"Petek" means "Friday" in English.
In this case, 'petki' is the plural form of 'petek', indicating multiple Fridays in the month of June.
Petki v juniju so vedno sončni in topli.
Fridays in June are always sunny and warm.
Here, 'petek' refers to a specific day of the week, specifically 'Friday'.
V petek bomo imeli piknik.
On Friday we will have a picnic.
Here, 'ta petek' means 'this Friday', which specifies the upcoming Friday.