Is this invention already made?

Yes. “Clap on, clap off.”

@kritiper Yes, but has the specific lightbulb invention done yet? I had a clapper before it hurt my hands to use.

Get a night-light that plugs into an outlet, or a bedside lamp.
I have used liquid fueled camp lanterns that take about 45 seconds to die out after being shut off…

@kritiper Has a timer on a lightbulb been invented /patented yet?

@all A 30 second countdown timer for the bed room lightbulb?

It’s already invented. Search for “lamp with timer” on amazon. Most of them are for projecting things on the ceiling and wall for kids. There are also nightlight with timers for kids, so they turn off after the kids go to bed.

You can also plug your lamp into a smart outlet, and then tell Alexa or Google Home to turn it off at after a specific time. “Hey Alexa, turn off the bedroom lamp in five minutes”.

Or you could do what most people do, which is have a lamp next to the bed that you can turn off from the bed. That doesn’t work for sleeping in the tub though.

Not on the light bulb itself, but they make wall outlets that incorporate this feature. You can vary the delay by 10, 20, 30, 40, etc. seconds depending on how many seconds you press the “off” part of the switch. That is, if you press it for 2 seconds, you get a 20 second delay, etc. I know. I have such a switch myself. Ask at any hardware store.

Yep, I have some like @2davidc8 just described. They give about 10 seconds to fade down if you tap them once and… ( thanks to @2davidc8 !!! ) I just tried it and he’s right – you can hold them down for a bit to get them to wait longer before turning off. I didn’t realize – that’s going to really help me get downstairs each night!

I don’t think you’d want to put the switch on the bulb. If the bulb failed you’d have the expense of replacing both the timer and the bulb. I can imagine a timer/switch on the wall outlet. You can also make a timer/switch adapter that fits between the bulb and the socket.

There are some fancy LED bulbs that do many things with a remote control: changing colors, dimming, rainbow, etc. They cost in the $7–10 range. I bought one at Lowe’s recently.

I like the suggestion about telling Alexa to do it.