As a little side discussion to this, I would say it really depends on the situation. Is this an hourly job we are talking about? Perhaps from a common courtesy, do not upset the apple cart perspective, he should have responded. However, if he was hourly and not on call, I am not sure one should expect a response. Is this a company provided cell phone?
Note: I am not responding to this from my perspective. I do check work emails regularly and even worked some over the holiday weekend as this is a busier time for me. However, I know from supervising hourly employees, who receive overtime, there can be labor laws that do not require hourly people to be tethered to work email/texts during their off hours.