Shahreman

You will see that I reverted your edit to Solar Hijri calendar because you appear to have fallen into the "everybody knows" trap. We have all done that! Yes, Omar Khayam's calendar was the foundation stone for all subsequent Persian/Iranian calendars but his calendar has been refined many times since. See Iranian calendars. --John Maynard Friedman (talk) 12:24, 24 March 2019 (UTC)Reply

@John Maynard Friedman:So if something falls in the category of historical background of another thing, but is not representing the whole background in details, it should be neglected from history section of that article? --Shahreman (talk) 12:35, 24 March 2019 (UTC)Reply

The problem was that you wrote that Khayam invented the modern calendar - he did not.

Thinking about this a bit more, what you could do is write maybe a section called 'Origin', where you borrow heavily from Iranian calendars#Medieval era: Jalali calendar, which describes the work of Omar Khayam in 1079 CE. (Strangely, Jalali calendar doesn't even mention him, you might want to fix that). You would need to say something in your new section about what has been changed in the past 940 years to reach the modern calendar, without effectively rewriting Iranian calendars article! By the way, don't forget if you do just copy material from another article (which is perfectly OK) you need to say in the edit note that you have done so. I hope this helps? --John Maynard Friedman (talk) 16:28, 24 March 2019 (UTC)Reply