I imagine there are some people who arrive/leave work at seemingly random times on successive days as a means of avoiding physical harm by others during the daily commute to and from home. This behavior is probably most common in metropolitan areas with heavily used public transportation systems. A subway passenger who gets on the train 10 minutes later each morning until Friday, at which point they arrive at work 40 minutes later than they had Monday, and then reverses the cycle the next week so that next Friday they arrive at the same time as their initial Monday is less likely to fall victim to burglary or death because their routine will be harder for potential criminals to pinpoint. This assumption relies on the idea that subway thugs prefer attacking someone who they’ve monitored for a few days. While this may not be true for even a majority of thugs, it certainly is true of some of them, and so the changing of work schedule is essentially immunity against these attackers. Moreover, the people who premeditate their attack are likely more dangerous than those who act on impulse. Also fun is that arriving at work later in the morning would have to be compensated by leaving later in the afternoon.