Hi,
Q1:
This is a bug, and We will try to fix it. This problem is brought up by the scientific notation of the value. By default, Origin will convert the value into scientific notation when upper threshold power is 6. Now, the Julian value is converted, which make it rounded. The workaround is:
1. Click menu Tools: Options to open the Options dialog.
2. Go to the Numeric Format tab, set Upper Threshold Power to 8, or bigger.
Q2:
You can try
tr.Root.Scale.IncrementBy.dVal = 0;
tr.Root.Scale.Value.strVal = "0.5day";
When zoom in the graph, the labels will change accordingly, which will make the label not display at "00:00" and "12:00". Currently, it seems no way to display in two lines.
Penn