When I observe the popular times of a store / place / online shop on Google,† sometimes the bar graph has one peak (maximum) but sometimes it has two (global maximum and a local maximum). I was thinking that the graph should approximate the Poisson distribution but it seems this is not the case for the graphs which have two peaks. So, I considered that the average rate λ is not constant for this case. Is there a distribution such as Poisson with a variable time rate λ ? What other distribution could I use to model / approximate the graphs which have two peaks ?
† See this Google Maps link for a steak restaurant in Paris and scroll down the left to see the barchart for "Popular times".