How to create XML-file for importing in MS Project correctly?

Hi, everyone!

I need to import data from my program using XML-file so, that there would be correct view of a project in MS Project. For example: I have 1 project with some tasks. Each task has got executor(resource). Also there is a calendar of holidays and weekends and calendar of absence for each executor. I want to see next properties of each task: Name, StartDate, EndDate, Duration, Predecessors, Executor. Tasks must be viewed as hierarchy. But I don't know, how to do it correctly.

There are a lot of kinds of date tags, which can be used, a lot of calendars. I don't know if I could configure the calendar with holidays in MS Project's settings, or I need to write it in XML-file for each of executors in addition to their absence data. 

I think, that too big amount of tags, using in XML-file is exessievely for my needs. So, that's really confusing, I don't know, how to start, and I haven't even found any useful articles by this subject.

If you think, that my question is not informative, please let me know and tell what moments I should reveal more deep.

All the helpful advice will are welcome))

Thanks.