CRM Web API: how to query data that current Date between date range

How I use javascript to call CRM Web API, I would like to query some data that current date between date range. But I cannot to use DateTime.Now() to get current date with javascript, because the date would be local time, it is not safe.

So is there any way can get the Current Date with CRM Web API?

Or is there any way can query data between date range?  I tried view, but I cannot find properly condition.