The full code would help to understand what the problem is.
Just a guess: Could it be that you try to address an element of an array with an index that is out o range?
Example:
// Define the array @ size of 2
byte anyArray[2] = {11,22};
// access first element with index 0
byte tmp_0 = anyArray[0];
// access second element with index 1
byte tmp_1 = anyArray[1];
In your extract I see:
... checkTimes[0].daysOfWeek[7] ... // i.e checkTimes[0].daysOfWeek[7] has (must have) 8 elements