//@version=6
indicator("Workshop 11 Anchored VWAP", overlay=true)
anchor = input.time(timestamp("01 Jan 2026 00:00 +0000"),
    "Anchor time")
active = time >= anchor
var float pv = 0.0
var float total = 0.0
var bool bad = false
if active
    bad := bad or na(volume)
    if not na(volume) and volume > 0
        pv += hlc3 * volume
        total += volume
value = (active and not bad and total > 0 ?
    pv / total : na)
plot(value, "Bar weighted VWAP", color=color.blue,
    linewidth=2, style=plot.style_linebr)
bgcolor(active and bad ? color.new(color.red, 88) : na)