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what is the timezone that yahoo uses for stock information
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using your example link, i found the corresponding chart for a stock that trades on london stock exchange: https://ca.finance.yahoo.com/echarts?s=rio.l#symbol=rio.l;range=1d as you can see there, the chart runs from ~8:00am to ~4:30pm, and as i write this post it is only 2:14pm eastern time.  so clearly this foreign chart is using a foreign time zone.  and as you can see from this wikipedia page, those hours are exactly the london stock exchange's hours. additionally, the closing price listed above the graph has a timestamp of "11:35am est", meaning that the rightmost timestamp in the graph (~4:30pm) is equal to 11:35am est.  16:30 - 11:30 = 5 hours = difference between london and new york at this time of year. so those are two data points showing that yahoo uses the exchange's native time zone when displaying these charts.
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