Ok, scenario from what I have observed... Fokker 50 lands (remote aerodrome) crew overnights. Went to dinner with the crew but no engineer. They depart the next day, no sign of an engineer.
The daily inspection certificate is valid until the end of the calendar day on which it expires, 24 hours after it is signed. Sign it at 6 am on the 1st - it runs for 24 hours (till 6 am on the 2nd) - and is valid until midnight of the 2nd.
Note: While pilots can't do the daily on a Class A aircraft, they are still responsible for the pre-flight inspection, the "walk around", to check for bird strikes, ramp rash (damage from ground equipment), FOD damage (stones kicked up by the tyres, puncturing the wings/flaps) etc.
The requirement to complete water checks on turbine aircraft changed around 1997. Until then, in Ansett, a fuel drain was completed after each refuelling and a water test (syringe and pellet usually) completed. As the test isn't particularly valid after mixing up Avtur during refuelling (it needs time to settle) the CAOs changed, and the drain was no longer required.