Modify Daves Soft latch power switch to require longer buttonpressing.

[ulfpe]

Hello, I need a soft latch power switch, I found Daves excellent circuit.
I need to modify it a bit, I would like the button to be pressed about 3 seconds before the mosfet turn on and pressing about 2 seconds  will shut it down.
How do I modify it to have this functionality?

[veryevil]

My first guess would be adding a large value cap to the base of the NPN transistor which the 100k Pull up on the other side of the switch will charge?

EDIT: Seems to work - See Spice Attached. Added 10u Cap and modded 100k to 1Meg

[ulfpe]

Thanks!