Η ημερομηνία αξίας είναι αύριο.

A simple breakdown is:

• Η = the; the feminine singular definite article
• ημερομηνία = date
• αξίας = of value; this is the genitive form of αξία
• είναι = is
• αύριο = tomorrow

So grammatically, the sentence is:

• Subject: Η ημερομηνία αξίας
• Verb: είναι
• Time expression / complement: αύριο

The key phrase is ημερομηνία αξίας, which functions as one unit.

Because ημερομηνία is a feminine singular noun, Greek uses the feminine singular definite article η.

So:

• η ημερομηνία = the date

At the beginning of the sentence, it is capitalized:

• Η ημερομηνία

Also, that letter is not the English H. It is the Greek capital letter Η / η (eta), and in Modern Greek it is pronounced ee.

So Η here sounds like ee, not h.

Because Greek often uses the genitive to show a relationship like of in English.

• αξία = value (dictionary form, nominative)
• αξίας = of value (genitive singular)

So:

• ημερομηνία αξίας literally means date of value

In natural English, that becomes value date.

This noun + genitive pattern is very common in Greek. English often uses noun compounds, but Greek often prefers this of relationship.

Because ημερομηνία αξίας is a set noun phrase, especially in financial or banking language.

Greek often leaves out the second article in combinations like this when the whole phrase works as a single term.

So:

• η ημερομηνία αξίας = the value date

If you added another article, such as της, the phrase would sound different and less like the standard technical term.

Here αύριο is being used as an adverb, meaning tomorrow.

Adverbs do not take articles in this use.

So:

• είναι αύριο = is tomorrow

Compare that with το αύριο, which can exist as a noun phrase meaning something more like the future or tomorrow as an idea. That is a different use.

In this sentence, αύριο is simply telling you when.

No. Greek word order is more flexible than English word order.

The sentence as given:

• Η ημερομηνία αξίας είναι αύριο.

is a neutral, straightforward way to say it.

But Greek could also say:

• Αύριο είναι η ημερομηνία αξίας.

That puts more emphasis on αύριο.

So the basic meaning stays the same, but the focus can shift depending on what comes first.

In a normal full sentence, you should keep είναι.

• Η ημερομηνία αξίας είναι αύριο. = normal sentence

Greek does sometimes omit forms of to be in headlines, labels, notes, or very compressed style, but that is not the standard full-sentence pattern.

So for learners, the safe rule is:

• if you are making a normal sentence, keep είναι

Also, είναι is the 3rd person singular/plural present form of είμαι = to be.

A good pronunciation guide is:

• Η = ee
• ημερομηνία = ee-meh-roh-mee-NYA or more carefully ee-meh-roh-mee-NEE-ah
• αξίας = ax-EE-as
• είναι = EE-ne
• αύριο = AV-ree-o

A more accurate IPA-style pronunciation is:

• [i imerominiˈa aˈksias ˈine ˈavrio]

A few useful sound notes:

• ει in είναι sounds like ee
• αι usually sounds like e, but in είναι the stressed εί is still ee because it is ει
• αυ in αύριο sounds like av here, because the following sound is voiced

The written accent marks show where the stress goes, and they matter in Greek.

Not really for casual daily conversation. It is mainly a technical financial/banking term.

You are likely to see it in contexts like:

• bank transfers
• statements
• transaction details
• accounting or payment systems

In ordinary conversation, people would more often just say ημερομηνία if the context is clear. But in finance, ημερομηνία αξίας is a standard term with a specific meaning.

ημερομηνία is in the nominative singular because it is the subject of the sentence.

You can see that from:

• the article Η
• the basic role of the phrase as the thing being talked about

So:

• Η ημερομηνία αξίας = the subject
• είναι = the verb
• αύριο = tells when

Meanwhile, αξίας is in the genitive singular because it depends on ημερομηνία and means of value.