Η ημερομηνία έκδοσης είναι σωστή.

Η is the feminine singular definite article, so here it means the.

It is not pronounced with an English h sound. In Modern Greek, Η is pronounced ee.

So:

• Η ημερομηνία = the date

Also, even though it is written with a capital Η, that is just because it is the first word of the sentence.

In Greek, every noun has a grammatical gender: masculine, feminine, or neuter.
Ημερομηνία happens to be feminine, so it takes:

• the feminine article η
• the feminine adjective form σωστή

This is grammatical gender, not biological gender. English learners often have to get used to this, because English nouns usually do not work this way.

It is in the nominative singular.

Why?

Because η ημερομηνία έκδοσης is the subject of the sentence, and subjects are normally in the nominative.

So the structure is:

• Η ημερομηνία έκδοσης = subject
• είναι = verb
• σωστή = predicate adjective

Because έκδοσης is the genitive singular form of η έκδοση.

Greek often uses the genitive after another noun to mean something like:

• of
• related to
• belonging to

So:

• ημερομηνία έκδοσης literally means date of issue / date of publication

This is very common in Greek noun combinations.

Greek often leaves out the article in this kind of noun + genitive expression when it is being used in a general or standard label-like way.

So:

• η ημερομηνία έκδοσης = the issue date / publication date

You could also see:

• η ημερομηνία της έκδοσης

but that sounds more like the date of the specific issuance/publication, with extra emphasis on a particular έκδοση.

In many practical contexts, especially in formal or document language, ημερομηνία έκδοσης is the natural fixed expression.

Because the adjective must agree with ημερομηνία, which is:

• feminine
• singular
• nominative

The adjective σωστός has different forms:

• σωστός = masculine
• σωστή = feminine
• σωστό = neuter

Since ημερομηνία is feminine, Greek uses σωστή.

Here it is working as a predicate adjective, not as a directly attached adjective before the noun.

The sentence pattern is:

• Η ημερομηνία έκδοσης = the subject
• είναι = is
• σωστή = correct

So this is like:

• The issue date is correct

If you put an adjective directly with the noun, that is a different structure, for example:

• η σωστή ημερομηνία έκδοσης = the correct issue date

That means the adjective is inside the noun phrase, not after είναι.

No. Είναι does not change for gender.

It is the third person singular form of είμαι (to be), and it is used with:

• masculine subjects
• feminine subjects
• neuter subjects

So you can say:

• Ο αριθμός είναι σωστός
• Η ημερομηνία είναι σωστή
• Το όνομα είναι σωστό

The adjective changes for gender, but είναι stays the same.

Yes, Greek word order is more flexible than English word order.

The neutral, standard order here is:

• Η ημερομηνία έκδοσης είναι σωστή.

But Greek could change the order for emphasis, for example:

• Σωστή είναι η ημερομηνία έκδοσης.

That sounds more emphatic, something like It is the issue date that is correct.

For learners, the original order is the safest and most natural one to use first.

A rough pronunciation is:

• i imerominía ékdosis íne sostí

A few useful notes:

• Η sounds like ee
• ημερομηνία has the stress on -νί-
• έκδοσης has the stress on the first syllable
• είναι is usually pronounced íne in normal Modern Greek speech
• σωστή has the stress on the last syllable

So the rhythm is roughly:

• i i-me-ro-mi-NI-a EK-tho-sis I-ne so-STI

Yes, very much so. It is a common formal phrase, especially on:

• documents
• certificates
• IDs
• official forms
• published material

It functions almost like a set label meaning:

• date of issue
• issue date
• sometimes publication date, depending on context

So a learner should treat ημερομηνία έκδοσης as a very useful chunk, not just as three separate words.