Questions & Answers about Κάθε Παρασκευή τρώω γλυκό με τη φίλη μου.
Παρασκευή means Friday and, like the names of the days of the week and months, it is written with a capital letter in Greek: Δευτέρα, Τρίτη, Τετάρτη, Πέμπτη, Παρασκευή, Σάββατο, Κυριακή.
So yes, when you write the name of a day as a noun (like here), you capitalize it.
The word κάθε (every/each) normally goes directly before a noun without an article:
- κάθε μέρα – every day
- κάθε εβδομάδα – every week
- κάθε Παρασκευή – every Friday
Saying κάθε την Παρασκευή is ungrammatical in modern standard Greek.
You just use κάθε + noun with no article.