When we are talking about a future arrangement, that is planned and we believe 100% organised, we can use the present continuous tense.
Examples:
We’re having a party this weekend.
We’re going shopping this afternoon.
She’s seeing a play on Saturday evening.
I’m watching my sister’s kids these holidays.
Note that we also often use going + infinitive verb to talk about future intentions. This works particularly well when it hasn’t been completely confirmed/organised, but we can use it for that too.
Examples:
I’m going to get a dog when I get my own home.
We’re going to have a party soon.
I’m going to try out that new restaurant when I get a chance.