shinyServer(function(input, output, session) {
  observe({
    # We'll use the input$controller variable multiple times, so save it as x
    # for convenience.
    x <- input$controller
    updateDateInput(session, "inDate",
      label = paste("Date label", x),
      value = paste("2013-04-", x, sep=""),
      min   = paste("2013-04-", x-1, sep=""),
      max   = paste("2013-04-", x+1, sep="")
    )
  })
})Run the code above in your browser using DataLab