Trying to get a timeline using the lab code

[gallivanting1]

I am not a photography enthusiast but thought perhaps someone here could offer some insight.

My grandfather passed away and my family has asked me to try and sort through his photographs. Like most people, he has these stored in no particular order in 4 large boxes. There are no dates on many of them and many are not grouped in the envelopes they would have been in from the film lab.

So far I have been able to sort them by the type of paper used (Kodak, Agra, Konica, Fujifilm and so on) and by the coding used in the developing process.

My problem is trying to get a timeline on these. Does anyone know what the code that the lab puts on the back of the photographs means and whether or not it could be used to determine when the photos were developed?

Any assistance you could offer would be greatly appreciated.

Thanks