As you can see, there are lots of variables to answering the how long is hamburger meat good for question. Raw hamburger meat (ground beef) is much more perishable than other cuts of beef and will keep in the refrigerator for only 1 to 2 days. Cooked hamburger meat will keep 3 to 4 days in the refrigerator.
Re: Poured side walk/steps, how long to leave forms? I strip the forms 24 hours later, but am careful not to damage the new concrete. It will still be very soft and with crumble if you put too much force on the edges. Usually concrete will harden withing 30 days to the point where it is considered cured.
If you poured your concrete in the middle of dry summer then 14 days should be the minimum amount of time you should wait. After you seal the concrete (depends on conditions and sealer product) you will typically want to give the sealer 1 day prior to walking on it and 48 hours after application before driving on it.