It was indeed a shitty situation for him.
The date on his watch indicated that it was fifteen days later, that was to say, he had spent fifteen days in the zero-dimensional space!
He was sure that he had only spent one day in the zero-dimensional space. He had many experiences in entering the zero-dimensional space, so he believed that his estimation was correct. Although the time in the zero-dimensional space couldn't be accurately calculated, even if the time perception in the zero-dimensional space wasn't exactly the same as the outside world, the difference wouldn't be that big.
Previously, when he used the strange seed inside the gigantic tree to enter the zero-dimensional space, it would cause his consciousness to black out for a period of time, and during this period of time, he would not be able to estimate time accurately. It was the main reason why there was time confusion when he came out last time.