‘Bryn_Wordhunt’ has provided verifiable evidence from 1978.
In Britain, a gap year is a period of time taken by a student between leaving school and starting at university, which is typically spent working or travelling. When we first published an OED entry for the term in 2001, the earliest evidence was from 1985, from the Times:
Many young people are making deliberate decisions to take a year off, often referred to as the gap year. This year is frequently split between some form of voluntary service or travel and a period in industry.
1985 Times 9 Dec., p. 28
However, we have now found an earlier use in the title of a 1984 book by Joan Hills, titled Jobs in the ‘Gap’ Year. Moreover, we suspect there may be even earlier evidence for gap year than this, perhaps in a student newspaper or university information leaflet. Can you help us find it? The original 2001 entry from online is below, for reference.
Posted by OED_Editor on 27 February 2013 14.10