1 year, before submission of dissertation. I.e 3 to 6 months time in social science and education. Because if we collect primary data and if submit after 2 years, no validity of findings derived and useful to society. Of course, if only for degree, it is flexible.
In my college, most of the people are finding that their research data is becoming outdated in a span of 3 years time. So, it is not advisable to simply stretch the time limit.
time limitation allows us to gather relevant data about some relevant problematic issues. it encourages us to organize our data gathering as soon as possible. if not, the problem is perished or solved.
Less than three years ... but the decision to submit research during the year to study and give results and the rest can extend to less than three years as in the doctoral students .....
Data collection is very important for writing a research paper, an MA thesis or a dissertation. The duration of time allocated for finishing the research depends on the nature of the research and time constraints set by the educational institution for its submission.
It depends on the subject. If it is a social science study particularly related to changing demographics or population characteristics or health issues or medicine it should be published with reasonable speed, for example, less than 2 years of data collection. For other areas of theoretical scientific research such as theoretical physics or math, the expediency to publish is not that critical. If it is a cutting edge technology or innovation there is need to publish or patent as quickly as possible because information in engineering/technology may get old fast.