Put yourself in the shoes of a criminal.
If you were trying to steal jewelry without anyone immediately noticing, when and how would you do it?
Robberies are about being noticed through force or fear, so that is too brazen to go unnoticed. Sneak, distraction, and switch thefts take a well-orchestrated effort to pull off, so that may be too difficult for most people to accomplish.
However, you notice that a jeweler has changed their hours for the holidays or a special event. After a few weeks of casing, it becomes clear that the physical, electronic, and procedural security of this particular jewelry business makes them an easy target during the planned absence from their regular routine.