Yahoo data changed from EST to UTC?

[man-chan]

I'm not sure is my bug or Yahoo or yFinance. Since I didn't log the command I used, so I guess the command should look similar to the following. Not sure the change in Yahoo data or yFinance.

This week, I got saved 2025-02-14 data as follow. I am using yFinance 0.2.54 & python 3.9.

yf.download('SPY', '2025-02-08', '2025-02-22', interval='1h', progress=False)

2025-02-14,09:00:00,609.31,610.5,609.22,610.26,0
2025-02-14,10:00:00,610.33,610.51,609.41,609.74,0
2025-02-14,11:00:00,609.73,609.74,608.67,608.73,0
2025-02-14,12:00:00,608.73,609.3,608.6,609.1,0
2025-02-14,13:00:00,609.11,611.0,608.76,609.39,0
2025-02-14,14:00:00,609.45,610.0,609.02,609.845,0
2025-02-14,14:30:00,609.9400024414062,610.989990234375,609.760009765625,610.239990234375,5214577
2025-02-14,15:30:00,610.239990234375,610.8499755859375,609.4000244140625,609.989990234375,3910433
2025-02-14,16:30:00,610.010009765625,610.2949829101562,609.27001953125,609.3201293945312,2764489
2025-02-14,17:30:00,609.3499755859375,610.0900268554688,609.0700073242188,609.9298706054688,1443250
2025-02-14,18:30:00,609.9299926757812,610.7506713867188,609.8800048828125,610.1300048828125,2059667
2025-02-14,19:30:00,610.1500244140625,610.3024291992188,609.5900268554688,609.6699829101562,2430485
2025-02-14,20:30:00,609.6599731445312,610.2899780273438,609.5449829101562,609.7000122070312,5528441
2025-02-14,21:00:00,609.69,610.0901,609.42,609.928,0
2025-02-14,22:00:00,609.93,609.95,609.66,609.83,0
2025-02-14,23:00:00,609.78,609.88,609.47,609.625,0
2025-02-18,09:00:00,610.77,611.91,610.77,611.51,0

Last week, I got the saved data, I was using 0.1.69 (worked like this for years).

yf.download('SPY', '2025-02-01', '2025-02-15', interval='1h', progress=False) 

2025-02-14,04:00:00,609.31,610.5,609.22,610.26,610.26,0
2025-02-14,05:00:00,610.33,610.51,609.41,609.74,609.74,0
2025-02-14,06:00:00,609.73,609.74,608.67,608.73,608.73,0
2025-02-14,07:00:00,608.73,609.3,608.6,609.1,609.1,0
2025-02-14,08:00:00,609.11,611.0,608.76,609.39,609.39,0
2025-02-14,09:00:00,609.45,610.0,609.02,609.845,609.845,0
2025-02-14,09:30:00,609.9400024414062,610.989990234375,609.760009765625,610.239990234375,610.239990234375,5214577
2025-02-14,10:30:00,610.239990234375,610.8499755859375,609.4000244140625,609.989990234375,609.989990234375,3910433
2025-02-14,11:30:00,610.010009765625,610.2949829101562,609.27001953125,609.3201293945312,609.3201293945312,2764489
2025-02-14,12:30:00,609.3499755859375,610.0900268554688,609.0700073242188,609.9298706054688,609.9298706054688,1443250
2025-02-14,13:30:00,609.9299926757812,610.7506713867188,609.8800048828125,610.1300048828125,610.1300048828125,2059667
2025-02-14,14:30:00,610.1500244140625,610.3024291992188,609.5900268554688,609.6699829101562,609.6699829101562,2430485
2025-02-14,15:30:00,609.6599731445312,610.2899780273438,609.5449829101562,609.7000122070312,609.7000122070312,5528441
2025-02-14,16:00:00,609.69,610.0901,609.42,609.928,609.928,0
2025-02-14,17:00:00,609.93,609.95,609.66,609.83,609.83,0
2025-02-14,18:00:00,609.78,609.88,609.47,609.625,609.625,0
2025-02-14,19:59:57,609.8,609.8,609.8,609.8,609.8,0

This is how I save the data

df.to_csv(filename, encoding='utf-8', columns=columns, index=False, compression='gzip')

I am still investigating the discrepancy, and I guess because the end date is exclusive, so I will need to advance one day to pull the data today or I will hit the ticker delisted issue.

[ValueRaider]

That's a bug. Most recent change 4157b9e

Workaround = yf.Ticker("SPY").history(...)

[man-chan]

Thank you. I manage to pull the data as you suggest.

df = yf.Ticker('SPY').history(interval='1d', start='2025-02-03', end='2025-02-07')

For the clarity, I would like to specify the date with the timezone. Not sure whether this is consistent with the design?

ticker = yf.Ticker('SPY')
ticker._tz = 'UTC'
df = ticker.history(interval='1d', start='2025-02-03', end='2025-02-07')

If possible, I prefer the code take the timezone from start and end datetime objects. Currently yf ignore this information.