I have Raspberry Pi 2 B running as home automation server. I use crontab to example send weather conditions to my whatsapp and measure temperature and humidity in my living room. Today there was no message and when I logged in I noticed crontab was empty. I believe this has happened to me once before. This is not a april fools joke, but an idea came to mind. Could this be something related to change of month? It might have been first of march when this happened before, not sure.