a1 <- seq(as.Date("1910/1/1"), as.Date("1910/3/31"), "days")
b1 <- rbinom(length(a1), 10, prob = 0.2)
a1 <- data.frame(type = "Breed", Date = rep(a1, times = b1))
a2 <- seq(as.Date("1910/2/1"), as.Date("1910/5/31"), "days")
b2 <- rbinom(length(a2), 10, prob = 0.3)
a2 <- data.frame(type = "Feed", Date = rep(a2, times = b2))
a3 <- seq(as.Date("1909/12/1"), as.Date("1910/4/30"), "days")
b3 <- rbinom(length(a3), 10, prob = 0.25)
a3 <- data.frame(type = "Overwinter", Date = rep(a3, times = b3))
dat <- rbind(a1, a2, a3)
boxplot(Date ~ type, data = dat, horizontal = TRUE)