At what milage should the platinum plugs on a 2008 Honda Accord be replaced?

This would equivalent to OEM
Iridium spark plug
Bosch part #9614 around 6.99 each

You can run other Bosch plugs from copper and up but you car calls for the iridium plugs hope this helps..
Dennis.....

If you need further help, reach me via phone at https://www.6ya.com/expert/dennis_f849d3d6a68c6430

This post may be an old post, but I figured I'd post my findings in case anyone is still fighting the good fight.
My vehicle:
2008 Honda Accord 2.4L EX-L
Codes: P062f p060a p2610 p2118
Hard starting when cold or sitting for over 25 min. Otherwise would start fine and drive fine with no issues until next start.
Process:
Replaced battery, no change
Sent Pcm (ecu) for repair/service. ECU came back with no errors or damage found. No change.
Replaced throttle body, no change.
Cleaned map and maf sensors, no change. (This fixed issue for someone so figured I would inspect.)
Replaced FTP, code went away, but no change.
*Note: During idle, I noticed a minimal sputter. Almost not audible.
Researched more, and one person mentioned they changed the spark plugs and that fixed their car.
So, I produce a list of all possible fuel/Ignition related possibilities for hard start/idle sputter.
Spark plugs
Ignition coils
Injectors
Fuel pump
As for me, I replaced the fuel injectors, ignition coils, and fuel pump about 2 years ago. And due to covid my car was almost not driven for the last 2 years. So, I removed them as possibilities for me. That left spark plugs.
I bought some NGK iridium plugs and replaced them. Old plugs were worn. (See pictures). This resolved my issues. No more cell lights, hard start, or idle sputter.
Definitely do your due diligence, but I'd say definitely go in this direction if your symptoms sound like mine did.
Good luck, everyone.

On this website, you find fuse box diagram and description for Honda Accord (2008 - 2009)
Honda Accord 2008 2009 fuse box diagram Auto Genius
Honda Accord (2011 - 2012)
Honda Accord 2011 2012 fuse box diagram Auto Genius

Refer to your owners manual for maintance schedule, should be more clarify there. Usually it's every 60-80 thousand milage

It should be replaced when you get to 60,000 miles.

Castrol extended milage oil. Go to Autozone and they will set you up with the correct rating 5w-30,10w-30 or whatever their specs say for the season of the year, as well as an oil filter and washer for the drain plug.

no, 12mm wrench or ratchet on 12mm socket. the piston is tough to push back in. its a twist in type and you will need some force to push and twist the piston back in. - note rear brake pads wearing out on the new 08-09 accords are very common and if under 16-18 thousand miles it may be covered. honda knows about this problem

I have known when the distributor starts to go bad it will not fire 100%, that could cause your failure in good gas mileage!

You have a timing chain not a belt. Happy motoring.