Marking sunrise and sunset on bottom axis

[wreeve]

I display a 24 hour time scale on my chart (86,400 seconds) and would like to place a vertical marker at the times for sunrise and sunset. For example, today the sunrise was 13:53 UTC and sunset will be 06:02 UTC.

The sunrise and sunset markers are not based on any chart data, and I cannot figure out how to place them. Of course, sunset is not here yet (at least for me) so I initially will only place a marker for sunrise. Later tonight I will place the sunset marker.

Has anyone figured this out? If so, how did you place the marker?

Thanks

Whit

[AzeoTech]

Use a line annotation. Set it to the bottom axis, and set the expression to a variable that contains the time of the next and prior sunrise/sunset values.

[wreeve]

That worked perfect! Thanks for helping me over the hump on that simple question.

Now, is it possible to show a shaded area between two times? For example, the area would extend the full vertical distance of the y-axis and extend horizontally between, say, sunset and sunrise times.

[AzeoTech]

No, not really. You might be able to achieve it by using a bar graph instead on the right axis, plotting a channel that goes to 1 at sunrise, and 0 at sunset, but you'd have to fiddle with it. It probably would work though. You could then add another trace that was the inverse and plot it a different color.

[wreeve]

I thought adding a vertical line on a certain time and date was working for me.

I used a line annotation and in the expression I put 10y04m30d 13h53m00.0 . This put a line on the chart at the correct time yesterday (30 April). I also put a line in for sunrise the next day: 10y05m01d 13h50m00.0.

However, now I have two line annotation at about the same time today (01 May), apparently ignoring the date specification. Maybe I am using an incorrect format in the expression field for the line annotation or I am missing something?

What should I be using in the expression field?

Thanks for your help

[AzeoTech]

You should use a variable instead and populate it from script. I doubt you want to be manually changing the sunrise/sunset values every day. You can create a table of all the values and look them up.