Hi Odeh,
the starting period is usually between 1-2 months and 6-8 months after you receive the offer, according to the following:
- Your needs: current job notice, graduation needs, family needs, etc
- Company needs: may depend on:
- Needs for current projects
- Expected needs for future projects (Summer/Winter breaks would play a role here as many projects starts in September or January in Western Europe and US)
The HR department is normally flexible on your needs, you can thus usually agree on a time good for both without issues.
Best,
Francesco