555 timer delay circuit + light sensor?
In the 555 circuit the capacitor controls the wait time, if the capacitor is short-circuited the circuit will wat forever.

In the LDR circuit the transistor acts like a switch but unfortunately it's switching to ground but the capacitor in the 555 circuit is connected to +9V 

To resolve this I swapped the parts in the 555 circuit upside down to have the capacitor to ground. Then it was simple to I merge the two circuits.







simulate this circuit &ndash; Schematic created using CircuitLab

In the dark R1 turns Q1 on the keesp C1 duscharged so 
555 output will be high

when there is light the LDR turns Q1 off and C1 charges , once it gets enough charge the 555 output goes low 

I could have instead built the upside-down version of the LDR circuit using a BC557 transitor (or other similar PNP type) instead of the BC547 NPN transistor and merged that with the original 555 circuit.