Skilled technique or enough time (more than one month) is regarded as necessary conditions to complete a handicraft
Xiao Zhou only took 25 days to complete a handicraft, which shows that Xiao Zhou has mastered skill
A criminal who commits a crime must have both the motive and the time. In a certain case, Mr. Li has the motive but no time to commit the crime, indicating that Mr. Li is not the perpetrator of the crime.