There is no time for light.
Fiber Optics use light pulses and patterns to transmit computer bits over vast distances in little time.
Extremely slow compared to quantum internet.
Light can be beamed into a FO cable and a networking card can decode the signal into language.

If you know what the pulse will look like (LIGHT) and you know WHEN you need it to be delivered, you could use a laser to inject bits and packets "from the future" into existing network traffic undetected from no observable or traceable source and appear authentic.

Consider several TS space missions over the past 5 years.
One of them was the machine used to send messages "forward in time".
Time is an illusion to the perception of the PLANE we live upon.
When you leave the plane, time is multi dimensional similar to the plane.

Light can be sped up and slowed down using lasers and bits can be slowly fed into existing FO data streams such that "completing a TCP packet" might take 6 months to complete. If the TTL is adjusted, the packet can still be validated, transmitted, and received as a Q post.

The subject is heavily classified and while this is not exactly how this technology works, it is a simplified concept that gives the general concept behind how messages can travel through time if you setup your delivery and receiving mechanism up properly.