La fecha de la reunión ha cambiado.

Because fecha is a feminine noun in Spanish, so it takes the feminine article la.

• la fecha = the date
• una fecha = a date

This is something you mostly have to learn with the noun. The ending -a often suggests a noun is feminine, and fecha follows that pattern.

De la reunión means of the meeting.

So the structure is:

• la fecha = the date
• de la reunión = of the meeting

Together:

• la fecha de la reunión = the date of the meeting / the meeting date

Spanish often uses de where English uses of or sometimes a noun used like an adjective.

For example:

• el libro de María = María’s book / the book of María
• la puerta de la casa = the door of the house

Because reunión is referring to a specific meeting, not just meetings in general.

• de la reunión = of the meeting
• de reunión would sound incomplete or unnatural here

Spanish usually uses the definite article more often than English does. If both speaker and listener know which meeting is being talked about, la is natural.

The accent mark shows where the stress goes: reu-nión.

Without the accent, Spanish pronunciation rules would make you stress a different syllable. The written accent tells you the stress falls on the last syllable.

So:

• reunión → stress on -ón

This is very common in words ending in -n or -s when the stress does not follow the normal pattern.

Ha cambiado is the present perfect:

• ha = has
• cambiado = changed

In Spain, the present perfect is often used for a change or event that is seen as relevant to the present situation.

So:

• La fecha de la reunión ha cambiado = the date of the meeting has changed

You could also hear:

• La fecha de la reunión cambió

But in Peninsular Spanish, ha cambiado is very common when the result matters now or the change is connected to the present.

It is the pretérito perfecto compuesto (present perfect).

It is formed with:

• haber in the present tense
  +
• a past participle

Here:

• ha = third person singular of haber
• cambiado = past participle of cambiar

Formula:

• ha + past participle

Other examples:

• ha llegado = has arrived
• ha terminado = has finished
• ha salido = has left

Because Spanish forms the present perfect with haber, not with ser.

So Spanish says:

• ha cambiado = has changed

not:

• es cambiado

English uses has/have as the auxiliary, and Spanish does something similar with haber.

Also, cambiar here is describing a change of state: the date changed. It is not a passive structure.

Because cambiar can work intransitively here, meaning it can describe that something changed without naming who caused it.

So:

• La fecha de la reunión ha cambiado = the meeting date has changed

This focuses on the result, not the person responsible.

If you want to say who changed it, you could say:

• Han cambiado la fecha de la reunión = They have changed the meeting date
• La empresa ha cambiado la fecha de la reunión = The company has changed the meeting date

Yes, but it means something slightly different in tone and structure.

• La fecha de la reunión ha cambiado focuses on the fact that the date is now different.
• Se ha cambiado la fecha de la reunión uses se and sounds more like the meeting date has been changed or they changed the meeting date, with the agent left unspecified.

So the original sentence is often the most natural if you simply want to say the date is different now.

Yes, Spanish word order is more flexible than English.

Both are possible:

• La fecha de la reunión ha cambiado
• Ha cambiado la fecha de la reunión

The version with the subject first is the most neutral and learner-friendly.

Starting with the verb can sound a bit more stylistic or can put slightly more focus on the fact of the change.

Because Spanish usually does not use subject pronouns unless they are needed for emphasis or clarity.

Here, the subject is already stated:

• La fecha de la reunión

So there is no need for a pronoun.

Spanish commonly leaves pronouns out when the subject is clear:

• He llegado = I have arrived
• Han salido = They have left
• La fecha de la reunión ha cambiado = The meeting date has changed

Cambiado is the past participle of cambiar.

For regular -ar verbs, the past participle ends in -ado:

• hablar → hablado
• cambiar → cambiado
• llegar → llegado

For regular -er and -ir verbs, it ends in -ido:

• comer → comido
• vivir → vivido

So:

• ha cambiado = has changed

The sentence itself is correct everywhere in the Spanish-speaking world. What is especially associated with Spain is how natural ha cambiado sounds in everyday use.

In Spain, speakers often use the present perfect for recent events or events connected to the present:

• Hoy ha cambiado la fecha = Today the date has changed

In many parts of Latin America, people might more often say:

• La fecha de la reunión cambió

Both are correct, but the preference can vary by region.