You can do with specials whatever you want.
For example, you can create a big sale "Black Friday" that will show only special price for certain products on Friday for the whole day or in particular hours. Or another example: you can use "Happy hours" for some products in your online store.
Set specials in certain weekdays (e.g. only on Friday, Sunday, and Monday)
Set specials in certain hours (e.g. from 3 PM to 5 PM)
Loop the special on certain days/hours
Set translation for the weekdays
See the current price with taking into account special weekdays and hours on the site and in the admin panel