To knock this one out, just come back five days in a row and complete at least one daily challenge from that day. This will unlock upon completion of one challenge on the fifth day.
If you're impatient and want it in one day then change the date on your computer to four days before the one you're on. Complete one challenge, then exit the game. Now set date to the next day and do a challenge from that day.
Repeat those steps until you have the previous four days done in sequence. Now set your date to the current day and complete your last challenge. Achievement unlocked, with a timestamp for the current date.
This must be done while online. Daily challenges will not load if you are disconnected from the internet.