Intriguing... but you haven't provided a definition of dimension.

Time can be squished, changed, modified in relation to various observers... just like i ⃗, j ⃗, k ⃗ can be.

An observer standing on Earth's surface might measure a space ship traveling at near light speed as a certain length. However, an observer within the space ship will have a very different measurement of the ship's length.

Time works the same way...

An observer travelling at near light speed will measure the passage of time running very slowly as compared to an observer standing on Earth's surface.

It's all Relative ... The term "dimension" needs to be firmly defined before one may have a discussion about what it means to be a dimension.