during and for

During is used to say when something happens; for is used to say how long it lasts. Compare:

• My father was in Germany during the summer.
  My father was in Germany for six weeks. (not … during six weeks.)
• It rained during the night for two or three hours.
  I’ll come and see you for a few minutes during the afternoon.

note

For for, since, in and from, (see here).