Vet Session Ranges

//@version=4
//
// Modified from @Lothalin's OM Session Ranges script
//
// This version displays tickers that use the Central Timezon, such as VIX
study("Vet Session Ranges", overlay=true)

central = (syminfo.timezone == "America/Chicago")

timeIsAllowedMorn = time(timeframe.period,(central ? "0830-0905:23456":"0930-1005:23456"))
var hiMorn = 10e-10
var loMorn = 10e10
if timeIsAllowedMorn
    if not timeIsAllowedMorn[1]
        hiMorn := high
        loMorn := low
    else
        hiMorn := max(high, hiMorn)
        loMorn := min(low, loMorn)


timeIsAllowedAft = time(timeframe.period,(central ? "1230-1305:23456":"1330-1405:23456"))
var hiAft = 10e-10
var loAft = 10e10
if timeIsAllowedAft
    if not timeIsAllowedAft[1]
        hiAft := high
        loAft := low
    else
        hiAft := max(high, hiAft)
        loAft := min(low, loAft)


plot(not(true and not time(timeframe.period,(central ? "0830-1230:23456":"0930-1330:23456")))? hiMorn : na, "Morning High",   color.rgb(0,255,0,0), 2, plot.style_circles)
plot(not(true and not time(timeframe.period,(central ? "0830-1230:23456":"0930-1330:23456")))? loMorn : na, "Morning Low",    color.rgb(255,0,0,0), 2, plot.style_circles)
plot(not(true and not time(timeframe.period,(central ? "1230-1500:23456":"1330-1600:23456")))? hiAft  : na, "Afternoon High", color.rgb(0,255,0,0), 2, plot.style_circles)
plot(not(true and not time(timeframe.period,(central ? "1230-1500:23456":"1330-1600:23456")))? loAft  : na, "Afternoon Low",  color.rgb(255,0,0,0), 2, plot.style_circles)