A perfect day consists in getting up early and doing lots of fun things.
A perfect day consists of getting up early and doing lots of fun things.
Use consist of + noun/-ing to say what something includes or is made up of: ‘The course consists of ten lessons.’ ‘The job consists of answering emails and preparing reports.’
Consist in + noun/-ing also exists, but it is formal and has a different meaning. We use it to say what the main part or quality of something is: ‘The beauty of the plan consists in its simplicity.’ ‘True happiness consists in being satisfied with what you have.’
In normal everyday English, consist of is usually the best choice.