Different market data providers having different data, who is right?

[Butterfly]

It seems that many market providers use the last 4 quarters to calculate PE, rather than the last full year data.

Forward PE with using analyst data... honestly from what I see, analysts are infrequently wrong so I don't find it useful.

there is obviously lag issues when using Fiscal Fully Year EPS for P/E, hence why forecast P/E is often better, even if some estimates are wrong

the Historical (aka Current) P/E is based on "old" data so you might miss your targets for your buying decision. A bit like using yesterday Technical Chart to make your trading decision today