Code change dates

Does anyone know off the top of their mind when any of the following issues became code?

Lintel flashing
Lintel weepholes
Safety glass
Hose bib backflow preventers
Pressure balance/thermostatic mixing control valves
Gas line drip legs
Bathroom ventilation fans
2 pool drains or anti vortex cover

Have you tried contacting your local CEO? Might be easier than trying to find all the amendments to the IRC yourself. Give you a good opportunity to gain a contact as well.

you should know that the IRC code dates are not adopted by each municipality at the same time and that date could and will vary with each different area you go to, from cities to towns, to townships, and counties. Each could adopt it with contingencies, omissions, and or limitations

why are these dates needed?

Very hard to find that info out and I do not see why it would matter.