Repeats role in S4C's new vision following budget cuts
S4C says it will offer a "season of repeats" in response to fewer viewers being available during the summer.
The Welsh-language channel has announced details of how it will cope with a 24% cut in its budget over the next four years.
S4C said it would make the most of its archive from the National Eisteddfod in early August until September.
The overhaul follows cuts to the channel's budget announced last year by the UK government.
An outline schedule shows that some long-running series are set to disappear or move and programmes after 2200 BST will consist almost entirely of repeats.
The channel has indicated that its coverage of Welsh sports fixtures and other major events will be largely unchanged.
It has also announced a new commissioning system which will see key programmes put out to open tender every three years.
S4C said its new programme schedule will put the emphasis on the evening hours which attract the most viewers.
S4C chief executive Arwel Ellis Owen said: "S4C is facing its future with confidence, despite the fact there is less money available as well as major changes to the way we are to be funded.
"The significant challenge we're facing means we have to think of creative, ground-breaking ways of developing the service during a period of change and convergence."
S4C said its programme budget for 2012 to 2015 would be a minimum of £65m a year, which compares to a budget of £83m in 2010 and £78.7m in 2011.
In 2012, the budget will be £67m, with the additional cash identified as part of an ongoing review of internal costs.
It has already been decided the channel will be funded from part of the BBC licence fee from 2013.
The channel pointed to research which showed there were "fewer people available to view during the summer months".
"From the week following the National Eisteddfod until the beginning of September there will be a season of repeats," said the S4C content document.
"This will mean that we will make the most of our archive, giving viewers the choice of asking for an opportunity to see a 'treasure' or an old favourite from the past.
"We will also provide another opportunity for the viewers to see popular series."
The broadcaster said it would continue its commitment to "catering for children and young people within the schedule".
It said detailed research had been carried out which formed the basis for its new approach.
Mr Owen, told BBC Radio Wales that the channel "had to accept reality" with the cuts.
"It's a whole world of difference... but I hope the new schedule will keep existing viewers and attract new ones," he said.
Stopping broadcasting during the day had been considered, he said, but that option was dismissed after viewers said they wanted adult programmes, and not just children's, to remain.
Mr Owen said most repeats would be after the "prime time" slot between 1800 and 2000 BST when the channel had most viewers.
There was also a new "creative partnership" with the independent programme makers, with 1,500 hours "going begging in 2012".
The future was positive "despite the cuts", Mr Owen added.