Other ways to talk about the future

We use it to express duty, make formal arrangements and formal instructions, and give orders. 

• I am about to go on a business trip tomorrow.
• Children under 10 are not to be left unattended in the theme park.

We use it when we speak about the immediate future; it is informal, and we use it in conversation.

•  I am about to leave for work.
• I think the film is about to start now.
• Hurry up! The bus is just about to leave.

We use it when we talk about the immediate future.

• They are at the point of divorcing.
• Scientists are on the brink of inventing coronavirus antibody tests

It refers to scheduled times.

• His flight is due to land at seven.
• The next train is due to arrive at four.

We can use the present simple to talk about facts, fixed future events, and schedules, which are unchangeable. 

• The term ends on 16th June.
• Our office closes next Friday at noon.