JeeLib breaks light sensor

I’m a student working on an Arduino light sensor for a greenhouse/terrarium. So far, the photocell is reading the light and working to turn the light on or off based on how bright the ambient light is. I tried to add JeeLib.h to replace the delay with sleepy. When I added JeeLib, it stopped working.
Here is the code being used:

#include <JeeLib.h>

ISR(WDT_vect) { Sleepy::watchdogEvent(); }
int  photocell  =  A0 ;    // Tell the Arduino which pin that the photocell is  attached to
int  PowerTail  =  13 ;     // Tell the Arduino which pin that the PowerTail is attached to
int  threshold  =  300 ;     // set the photocell threshold at 500

void setup() {
  // initialize the PowerTail as an output:
  pinMode(PowerTail, OUTPUT);
  // initialize serial communications:
  Serial.begin(9600);
}

void loop() {
  // read the value of the photocell:
  int photocellValue = analogRead(photocell);

  // if the analog value is high enough, turn on the PowerTail:
  if (photocellValue > threshold) {
    digitalWrite( PowerTail , HIGH); //fill in with what you named where the PowerTail is attached
for (byte i = 0; i < 120; ++i)
      Sleepy::loseSomeTime(60000);

  } else {
    digitalWrite(PowerTail, LOW); //fill in with what you named where the PowerTail is attached
  }

  // print the photocell value:
  Serial.println(photocellValue);
    delay(1);        // delay in between reads for stability
}

Why doesn’t it work when JeeLib is added? I want to run it from batteries, but not waste batteries every day or two.

Does it work when you comment out the call to loseSomeTime()?

Not sure about your logic- as written there is a delay of 120secs if the light is bright enough but no delay if its dark..