Days, Months, Seasons & Dates
You already know the words; this is the grammar that puts them in a sentence. THE DAY takes the ACCUSATIVE with no preposition: «τη Δευτέρα» means “on Monday”, «το Σάββατο» “on Saturday” - the article alone does the work English needs “on” for. THE MONTH takes the ACCUSATIVE for “in”: «τον Ιανουάριο», «τον Αύγουστο». THE SEASON takes σε + accusative: «την άνοιξη», «το καλοκαίρι», or με τον χειμώνα when it is the subject. THE DATE is where the two halves of this pair of lessons meet: a feminine ORDINAL plus the month in the GENITIVE - «η πρώτη Μαΐου» (the first of May), «η δέκατη Οκτωβρίου». The feminine is not arbitrary: it agrees with the understood noun η μέρα. In speech the everyday form uses στις + the cardinal instead: «στις 5 Μαΐου», «στις 25 Δεκεμβρίου». Note what the genitive month does to the tonos - Ιανουάριος → Ιανουαρίου, Αύγουστος → Αυγούστου - because it is the ordinary -ος noun rule, not a calendar quirk. Finally, one trap that is pure spelling: the day Δευτέρα is stressed on -τέ- while the ordinal feminine δεύτερη is stressed on δεύ-, and the day Τετάρτη likewise differs from the ordinal τέταρτη - but Τρίτη and Πέμπτη are identical to their ordinals apart from the capital letter.
The rule
You already know the words; this is the grammar that puts them in a sentence, and it is four separate patterns. The day takes the bare accusative with no preposition - the article alone does the work English needs “on” for. The month takes the accusative for “in”: τον Ιανουάριο, τον Αύγουστο. The season takes σε + accusative: την άνοιξη, το καλοκαίρι. The date is where the two halves meet: a feminine ordinal plus the month in the genitive - η πρώτη Μαΐου, η δέκατη Οκτωβρίου. The feminine is not arbitrary; it agrees with the understood noun for “day”. In speech the everyday form is στις plus the plain cardinal instead. One thing to watch in the genitive month: it is the ordinary -ος noun rule, not a calendar quirk, so the tonos moves - Ιανουάριος → Ιανουαρίου, Αύγουστος → Αυγούστου, Μάιος → Μαΐου.
Paradigm
| Case | Singular | Plural |
|---|---|---|
| Nominative | Ιανουάριος | Ιανουάριοι† |
| Accusative | Ιανουάριο | Ιανουαρίους† |
| Genitive | Ιανουαρίου† | Ιανουαρίων† |
| Vocative | Ιανουάριε† | Ιανουάριοι† |
- A month is normally used in the singular; the plural is the regular -ος pattern and is rare.
- The heavy endings -ου / -ων / -ους pull the tonos one syllable forward (Ιανουάριος → Ιανουαρίου).
- Masculine singular takes the distinct -ε vocative (like -ος nouns).
- Vocative plural equals the nominative plural.
| Case | Singular | Plural |
|---|---|---|
| Nominative | άνοιξη | ανοίξεις† |
| Accusative | άνοιξη | ανοίξεις |
| Genitive | άνοιξης | ανοίξεων |
| Vocative | άνοιξη† | ανοίξεις† |
- The -η / -εις class: the plural ending is -εις and the tonos moves to -νοί-.
- Vocative equals the nominative.
- Vocative plural equals the nominative plural.