I'm trying to get the timing of a user's click on a dynamically-generated image using Shiny and some Javascript. The app below reports the client's time as LATER than the time captured within the server, which is not desired. I'd like to capture the time given by the user's browser when they click on the image (this will prevent noise and delays from the trip from the client to the Shiny server). Any ideas?

The ultimate goal for the app is to calculate a "find time" -- the duration it takes for a user to click on a specific coordinate after the image appears in their browser.

library(shiny)
library(shinyjs)
options(digits.secs = 3)     # Modify and save default global time options


click.time.image.js <- "

  document.getElementById('img').onclick = function(){
      var the_time = new Date().getTime();
      console.log(the_time);
      // set input$client_time to the_time:
      Shiny.setInputValue('client_time', the_time)
}
        "

shinyApp(

  ui = fluidPage(
    useShinyjs(),
    sidebarLayout(
      sidebarPanel(
        p("When clicking on the histogram, I'd like to capture the client-side computer's time"),
        actionButton(inputId="new_image", label= "New Image")
        ),
      mainPanel(
        imageOutput("img", click = "photo_click"),
        textOutput("client_time"),
        textOutput("server_time")
      )
    )
  ),
  server = function(input, output) {

    output$img <- renderImage({
      input$new_image

      outfile <- tempfile(fileext='.png')
      png(outfile, width=400, height=400)
      hist(rnorm(100))
      dev.off()

      shinyjs::runjs(click.time.image.js)

      list(src = outfile,
           alt = "This is alternate text")
    },
    deleteFile = TRUE)



    output$server_time <- renderText({
      req(input$photo_click)
      server.time <- as.character(strptime(Sys.time(), "%Y-%m-%d %H:%M:%OS"))    # Time with milliseconds
      paste("SERVER TIME:", server.time)
    })

    output$client_time <- renderText({
      req(input$photo_click)
      req(input$client_time)
      client.time <- input$client_time    # Time with milliseconds
      client.time <- as.POSIXct(client.time/1000, origin="1970-01-01")
      paste("CLIENTs TIME:", client.time)
    })


  }
)