If you're referring to a PC, then you could try Piriform's Recuva - it's been giving me reliable recovery of almost any file format.
If you're referring to a phone, it depends on whether those files were on your phone itself or on an SD Card. If they were on an SD Card, then simply connect it to your PC and use Reciva again. If they were on your phone, then they may not be recoverable.
The important factor is that the disk or storage media on which those deleted files were on has not been used considerably after the time of deletion - otherwise the risk of them being over-written increases over time. "A day" doesn't really tell much. If you've copied, downloaded, transferred, or otherwise did a lot of file activity in that disk or storage media within a few hours, then "a day" isn't going to be short enough. But if you've switched your device off for most of the day, then "a day" is going to be long enough.
Anyway, let us know what happens.