I'm not sure if this works, but give it a try:
Create a logic_timer
In the keyvalue named Refire interval, type how long it should take for the door to open/close in seconds.
In the outputs tab, click add and type:
My output named: OnTimer
Targets entities named: "door name here"
Via this input: Toggle
Like I said, I'm not sure if this works, but I hope it does.