Suggestion: --day > success=day || error=night

A suggestion for an additional option, e.g. `--day`.

Would return success if true, and error if false. For stuff like: `sunshine --day &>/dev/null && echo "day" || echo "night"`

The issue proposes a new `--day` command-line option with exit success when it is day and an error status when it is night. Start by locating the CLI option handling and the existing sunrise/sunset status logic; done means the example command prints the expected result for both conditions.

Written by the indexing model from the issue text.