Hi Mohamad,Greetings from Syncfusion.Yes, the method DateTime.AddMilliseconds(Double) rounded the millisecond to nearest integer, as by the .Net documentation we can use DateTime.AddTicks (Double) method. One Millisecond = 10,000 ticks. So, we can add 5000 ticks for half millisecond. Even though the millisecond will always be rounded to nearest possible integer. We don’t have any other chance.