Exactly What must be the period that is chronological of in the process of writing a dissertation?

Exactly What must be the period that is chronological of in the process of writing a dissertation? The writer along with his supervisor (consultant) determine the chronological period independently. There aren’t any formally founded criteria. Chronological duration when you look at the study of the trend may be any, but still it must be trained by the subject under study; it should be in a way that the author can completely recognize the point and objectives associated with research.