The administration licenses, regulates, and provides financial assistance to small business investment companies and section 301(d) licensees (formerly minority enterprise small business investment companies).
Cured and Dry. Concrete continues to harden for several years after it is poured, but the standard period of initial curing is 28 days, or roughly one month. At this point, the concrete is very close to full strength and is ready to accept most commercially available sealants. However, sealers typically must be applied to dry concrete. You can test the concrete for moisture content by securing a piece of aluminum foil on the sidewalk with duct tape and waiting 24 hours. If the foil is dry when you remove it, the sidewalk is ready for sealing.
Good luck. Typical concrete takes 28 days (4 weeks) to cure. Prior to the 28 days concrete still has moisture in it that weakens the strength of the concrete. If you seal it prior to 28 days there is a chance you will be sealing in some of that moisture and hence weakening the integrity of the concrete.