This would be a ggplot2 based option
library(tidyverse)
dataset <- data.frame(stringsAsFactors=FALSE,
time = c("0:00", "0:15", "0:30", "0:45", "1:00", "1:15", "1:30",
"1:45", "10:00", "10:15"),
avg_holds = c(1.15, 0.396, 0, 4.76, 1.59, 0, 0, 0, 2.19, 3.65),
month = c("June", "June", "June", "June", "June", "June", "June",
"June", "June", "June")
)
dataset %>%
mutate(time = as.POSIXct(hms::parse_hm(time))) %>%
ggplot(aes(time, avg_holds)) +
geom_point() +
scale_x_datetime(date_labels = "%H:%M")
