Check If System Month IS Between A Certain Range

I think this is the end result I'm looking for? It's a real "Brain Baker" but I think it's logical? Correct me if I'm wrong. ;)

 //Send Brightness Detected Audio Resoponse Request to Voice Box Object
     IEnumerator BrightnessResponse(){
         //Check System Time if its between 5P$$anonymous$$ - 7A$$anonymous$$ then play message
         if (sysHour >= 17 && sysHour <= 7) {
             //Check $$anonymous$$onths For Winter
             if (sys$$anonymous$$onth >= 01 && sys$$anonymous$$onth <= 10) {
                 yield return new WaitForSeconds (0.5f); // wait time
                 VoiceBox VBbr = FindObjectOfType<VoiceBox> ();
                 VBbr.BrightnessDetected ();
                 //Send $$anonymous$$essage for $$anonymous$$essage Centre to display "BRHT LGHT DETECTED" message
                 $$anonymous$$essageCentre$$anonymous$$anager $$anonymous$$C$$anonymous$$bd = FindObjectOfType<$$anonymous$$essageCentre$$anonymous$$anager> ();
                 $$anonymous$$C$$anonymous$$bd.GoBrightnessDetected$$anonymous$$essage ();
                 print ("Brilliant Light Detected $$anonymous$$ichael - WINTER AT NIGHT");
             }
         }
 
         //Summer $$anonymous$$onths Time Check
         //Check System Time if its between 5A$$anonymous$$ - 9P$$anonymous$$ then play message
         if (sysHour >= 21 && sysHour <= 5) {
             //Check $$anonymous$$onths For Summer
             if (sys$$anonymous$$onth >= 03 && sys$$anonymous$$onth <= 09) { //$$anonymous$$ar. to Sept.
                 yield return new WaitForSeconds (0.5f); // wait time
                 VoiceBox VBbr = FindObjectOfType<VoiceBox> ();
                 VBbr.BrightnessDetected ();
                 //Send $$anonymous$$essage for $$anonymous$$essage Centre to display "BRHT LGHT DETECTED" message
                 $$anonymous$$essageCentre$$anonymous$$anager $$anonymous$$C$$anonymous$$bd = FindObjectOfType<$$anonymous$$essageCentre$$anonymous$$anager> ();
                 $$anonymous$$C$$anonymous$$bd.GoBrightnessDetected$$anonymous$$essage ();
                 print ("Brilliant Light Detected $$anonymous$$ichael - SU$$anonymous$$$$anonymous$$ER AT NIGHT");
             }
         }
     }
 
     //Send Darkness Detected Audio Resoponse Request to Voice Box Object
     IEnumerator DarknessResponse(){
         //Check System Time if its between 7Am - 5P$$anonymous$$ then play message
         if (sysHour >= 7 && sysHour <= 17) {
             //Check $$anonymous$$onths For Winter
             if (sys$$anonymous$$onth <= 02 && sys$$anonymous$$onth <= 10) { //Feb. to Oct.
                 yield return new WaitForSeconds (0.5f); // wait time
                 VoiceBox VBdr = FindObjectOfType<VoiceBox> ();
                 VBdr.DarknessDetected ();
                 //Send $$anonymous$$essage for $$anonymous$$essage Centre to display "A$$anonymous$$B LGHT INSUF" message
                 $$anonymous$$essageCentre$$anonymous$$anager $$anonymous$$C$$anonymous$$dd = FindObjectOfType<$$anonymous$$essageCentre$$anonymous$$anager> ();
                 $$anonymous$$C$$anonymous$$dd.GoDarknessDetected$$anonymous$$essage ();
                 print ("Darkness $$anonymous$$ust Not Be Naturally Occuring $$anonymous$$ichael - WINTER AT DAY");
             }
         }
 
         //Summer $$anonymous$$onths Time Check
         //Check System Time if its between 5Am - 9P$$anonymous$$ then play message
         if (sysHour >= 5 && sysHour <= 21) {
             //Check $$anonymous$$onths For Summer
             if (sys$$anonymous$$onth >= 03 && sys$$anonymous$$onth <= 09) { //$$anonymous$$ar. to Sept.
                 yield return new WaitForSeconds (0.5f); // wait time
                 VoiceBox VBdr = FindObjectOfType<VoiceBox> ();
                 VBdr.DarknessDetected ();
                 //Send $$anonymous$$essage for $$anonymous$$essage Centre to display "A$$anonymous$$B LGHT INSUF" message
                 $$anonymous$$essageCentre$$anonymous$$anager $$anonymous$$C$$anonymous$$dd = FindObjectOfType<$$anonymous$$essageCentre$$anonymous$$anager> ();
                 $$anonymous$$C$$anonymous$$dd.GoDarknessDetected$$anonymous$$essage ();
                 print ("Darkness $$anonymous$$ust Not Be Naturally Occuring $$anonymous$$ichael - SU$$anonymous$$$$anonymous$$ER AT DAY");
             }
         }
     }

Your if statements are a bit screwy.

 if (sys$$anonymous$$onth <= 2 && sys$$anonymous$$onth <= 10) will only ever be true for values <= 2
     
     Should be (>= 2 && <= 10) so the value you are looking for is greater than or equal to your lowest value 2 and less than or equal to your highest value 10.

Why not use DateTime?

 if (DateTime.Now.IsDaylightSavingTime())
 {
     // Shenanigans!
 }