Yes, that would be similar to a linear X axis, but the data is not (always) evenly spaced.
For decimal UTC years [unit="years"], you could have :
Xdata [2012.0423, 2012.1156, 2012.2451, 2012.35564, 2012.7203, 2012.8546, 2012.9029, 2012.9845]
For julian dates, that's similar to decimal UTC years but the unit is "days" instead of "years".
Yes, that would be similar to a linear X axis, but the data is not (always) evenly spaced.
For decimal UTC years [unit="years"], you could have :
Xdata [2012.0423, 2012.1156, 2012.2451, 2012.35564, 2012.7203, 2012.8546, 2012.9029, 2012.9845]
For julian dates, that's similar to decimal UTC years but the unit is "days" instead of "years".