msg.payload.altitudePercent Is negative at night

[gobigdave]

Describe the bug
Sending a timestamp into sun-position node at night results in msg.payload.altitudePercent < 0%. My expectation and the doc indicates that this should be 0-100% only.

Screenshots
If applicable, add screenshots to help explain your problem.

Expected behavior
I expect msg.payload.altitudePercent to be between 0 and 100.

System information (please complete the following information):

• Latest node version
• Latest Node-Red Version
• Running as an add-on in Home Assistant OS

Additional context
This has worked fine for years. Only recently started acting funny.