At the end of your studies
Under the current UK immigration rules, you should be granted your visa for the length of your course with an additional period of up to 6 months (depending on your programme of study), known as the 'wrap-up period'.
These additional months are in the rules to allow people to attend their graduation and make any necessary arrangements for leaving the UK. In the case of those staying on in the UK, this period can be used for applying for a new visa in order to work or undertake further studies.
It is also in this period of time that people who have a standard work condition (up to 20 hours per week) will be able to work full time and on a temporary basis up until the end of their visa.
Short term students
Although your visa may be granted for six months, you are required to leave the UK within 30 days of the end of your studies.