This is the non-BS answer from ACI (similar to USACE specifications)
http://www.concrete.org/FAQ/afmviewfaq.asp?faqid=28:
Technical Questions - ACI Concrete Knowledge Center
Stripping time for forms
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Q. Does ACI provide information on how long to wait before stripping forms?
A. There are some important general requirements related to stripping time in ACI 318-05, Building Code Requirements for Structural Concrete. Section 6.2.1 states:
“Forms shall be removed in such a manner as not to impair safety and serviceability of the structure. Concrete exposed by form removal shall have sufficient strength not to be damaged by removal operation.”
There are additional default requirements contained in 301-05, "Specifications for Structural Concrete," the primary one being in Section 2.3.2.5:
“Unless otherwise specified, leave formwork and shoring in place to support the weight of concrete in beams, slabs, and in-place structural members until concrete has reached fc′…”
ACI 347-04, “Guide to Formwork for Concrete,” Section 3.7.1, gives direction regarding who is responsible for determining when the form stripping operation can begin:
“Although the contractor is generally responsible for design, construction, and safety of formwork, criteria for removal of forms or shores should be specified by the engineer/architect.”
As stated in ACI SP-4, Formwork for Concrete:
“Since early form removal is usually desirable so that forms can be reused, a reliable basis for determining the earliest proper stripping time is necessary. When forms are stripped, there must be no excessive deflection or distortion and no evidence of cracking or other damage to the concrete, due either to removal of support or to the stripping operation. Supporting forms and shores must not be removed from beams, floors, and walls until these structural units are strong enough to carry their own weight and any approved superimposed load, unless provision has been made to allow for anticipated temporary construction loads, as for example in multistory work. In no case should forms and shores be removed from horizontal members before concrete has reached the strength specified by the engineer/architect for form removal.”
ACI 347.2R-05, “Guide for Shoring/Reshoring of Concrete Multistory Buildings,” provides detailed information regarding the practice of stripping formwork and placing reshores in multistory building construction.