“It's just been one of those days.”

Today you went to work looking messy and scruffy because you woke up late, spilled some coffee on yourself, and had a few other accidents. A coworker is asking if you're OK because of how you look. You say:

It's just been one of those days.

It's been one of those days.

This is a set expression that people say when:

• they've had a bad day
• they've been really busy all day
• a lot of unlucky accidents happened

Any of these can be described as "one of those days".

People often use this phrase at work. For example, if someone seems to be stressed out at work you can say to them:

One of those days, huh?

If a coworker tells you that they've "had one of those days", you don't necessarily have to ask them about it. Part of the attitude that this phrase expresses is the feeling that bad days sometimes happen and can't be helped.