That familiar fixture, the charity of the year partnership, is fast becoming a misnomer. It is not disappearing - far from it. But the time-span is lengthening. More often than not, the traditional 12 months is now stretched to 24 or 36.
Morrisons' partnership with Save the Children illustrates this change. Originally conceived in 2011 as a year-long fundraising partnership, it was extended first to two years and then to three.
This is new ground for Morrisons, whose previous charity of the year partnerships with, for example, the health charities Help the Hospices and Asthma UK, all lasted the more usual 12 months.
The fundraising total of £7m resulting from its work with Save the Children is the largest a Morrisons charity partnership has ever generated, both on a pro rata basis and as a final amount.
"We took advice from the Charities Aid Foundation about the best length of time for a partnership," says Guy Mason, head of corporate affairs at Morrisons. "CAF said the optimum time was three years."
That advice has proved inspired as fundraising has risen from £2m in 2011 to £2.9m in 2013. The increase has come about partly because the supermarket and Save the Children have widened their activities to include international appeals - such as its in-store bucket collections in 2013 - rather than focus only on the charity's UK projects, such as Families and Schools Together, as it has done in previous years.
Morrisons' new partnership with the disability charity Sue Ryder is now intended to last three years.