Next or the next?

Next or the next?

When we talk about days of the week, weeks, months, years, seasons or public holidays in the future in relation to now, we use next without the and without a preposition:

I have an appointment with the dentist next Wednesday morning.
Not: … the next Wednesday morning.
Are you working next week?
Not: Are you working on next week?
Next year will be our fortieth wedding anniversary.
We’re going to plant some new flowers next spring.
To refer to the future, we can use the next few hours, the next two days,the next six months, etc.:
I’ll finish the work in the next few days. You can pay me then.
We’ll be home for the next three weeks, then we’re going away to France for two weeks.

When we talk about times in the past or future not related to now, we normally use the. However, in informal situations, we can omit the when we talk about the past:

The next day we travelled to the ancient city of Qom.
We’re going to spend the first night in Oslo, then the next day we’ll fly to Narvik.
Two policemen grabbed me. Next minute, I was arrested and thrown into a van.