Sometimes students use phrases like ‘the next next day’, ‘the day before before’, ‘tomorrow’s tomorrow’, or ‘yesterday’s yesterday’. This isn’t very good English.

tomorrow’s tomorrow

the day after tomorrow
in 2 days time

yesterday’s yesterday

the day before yesterday
2 days ago

If counting forward from a day in the future or past, use ‘the day after’ or ‘the day before’.

I will go to Beijing on the 19th. On the 19th’s tomorrow, I will go to Xining.

I will go to Beijing on the 19th. The day after that I will go to Xining.

I will go to Beijing on the 19th. On the 19th’s yesterday I will be in Xi’an.

I went to Milan for the football game. The game’s tomorrow I came home.

I went to Milan for the football game. I bought my ticket that day’s yesterday.

I will go to Beijing on the 19th. The day before that, I will be in Xi’an.

I went to Milan for the football game. The day after, I came home.

I went to Milan for the football game. I bought my ticket the day before.