As your tags indicate iOS, one can pursue the ringtone option built into the Apple architecture.
One can set an alarm for every day, at a specific time. The next step is to assign the desired ringtone representing the custom audio clip to that alarm. This feature is built into the alarm settings, specific for the time referenced for the alarm.
A video showing the process of converting a song to a ringtone involves a ringtone app (free) and converting using GarageBand. It appears rather convoluted, but is a sound solution, no pun intended.
The above process references a 30 second time limit, but searching that set of terms shows another process to increase the limitation, should your desired song be longer than 30 seconds.
I've taken a more direct route (possibly not more direct) by using Audacity to import the audio clip/song. Editing is straight forward in Audacity. Once completed, save the file as .M4A (.m4a) format. Rename the file to .M4R (.m4r) and transfer to the Apple device. I've found it easier to use iTunes to drag and drop the .m4r file to the ringtones section of the device, although it can be emailed to the device as well.