Earning date questions

[blackice]

Hi guys,

I'm writing program to do analysis and filtering on option historical data. I have a few questions:

1. where to find historical earning dates for a stock? Nasdaq website has 4-5 previous earning dates but that's it, I want for about 5 years.

2. what's the reliable source to find incoming earning date?

3. why would companies disclose earning date before head? why not just disclose a date range (like a week) and publish their earning on an arbitrary day within that week?

4. how often do companies disclose earning date but actually publish earning on different day (which is misleading)?

 

Thank you all.

[Kim]

1. I'm using https://www.optionslam.com/. You can get a discount for subscription - https://steadyoptions.com/articles/optionslam-discount-for-steadyoptions-r112/
2. Same. There are other sources, but the ultimate source is the company website.
3. Stock market needs certainty. For example, many options traders (like us) trade earnings and need to know the exact date.
4. It is not common, but it happens from time to time.

[wr200m]

@blackice, i think Yahoo Finance has this business calendar you get to scrape. For instance: 

https://biz.yahoo.com/research/earncal/20150203.html.

Ycharts also has it but I don't know if they can be as tolerant as Yahoo for robots. I also have a plan to do this maybe next month as an exercise.