Macro day_start 

macro_rules! day_start {
    ($root:expr) => { ... };
    (options: $options:expr, $root:expr) => { ... };
    ($title:expr, $root:expr) => { ... };
}

One entry point for every platform that needs one: the single line an app’s lib.rs carries instead of one macro per platform.

day::day_start!("My App", root);    // or: day::day_start!(root);

It expands to every platform macro below. Each of those is gated on its own target (ios / macos / android / the ohos env / wasm32), and those gates are mutually exclusive, so exactly one survives a given build, and none at all on a plain cargo desktop build, where src/main.rs is the entry instead.

The title reaches the platforms that have nowhere else to get one. Android and HarmonyOS take their label from the app manifest (android:label, app_name in string.json) rather than from Rust, so they accept the argument and ignore it; passing it here keeps one call site for every target instead of making the caller remember which two are different.