radio: quiet hours for reminders (default 23:00-07:30 Amsterdam, RADIO_QUIET_HOURS overrides)

src/lib/radio/index.ts

@@ -40,6 +40,20 @@ export const ALPHA_TAG_MAX = 16;
 export const ISS_MIN_EL = 10;
 export const REMIND_MINUTES = 10;
 export const ISS_DOWNLINK_HZ = 145_800_000;
+/** No reminders are sent when the send time falls in this Amsterdam window (RADIO_QUIET_HOURS overrides). */
+export const QUIET_HOURS = '23:00-07:30';
+export type Quiet = { from: number; to: number; label: string } | null;
+/** "23:00-07:30" -> minutes of day; "off" / "" -> null (no quiet hours). */
+export function parseQuiet(spec: string | null | undefined): Quiet {
+	const m = /^\s*(\d{1,2}):(\d{2})\s*[-–]\s*(\d{1,2}):(\d{2})\s*$/.exec(spec ?? '');
+	if (!m) return null;
+	const from = Number(m[1]) * 60 + Number(m[2]);
+	const to = Number(m[3]) * 60 + Number(m[4]);
+	if (from > 1440 || to > 1440 || from === to) return null;
+	const pad = (n: number) =>
+		`${String(Math.floor(n / 60)).padStart(2, '0')}:${String(n % 60).padStart(2, '0')}`;
+	return { from, to, label: `${pad(from)}–${pad(to)}` };
+}
 
 export const DAY_SHORT = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun'] as const;
 
@@ -312,3 +326,11 @@ export function alphaTag(name: string, marineCh?: string | null): string {
 	if (marineCh) s = `${marineCh} ${s}`;
 	return s.slice(0, ALPHA_TAG_MAX).trim();
 }
+
+/** Whether an instant falls in the quiet window (Amsterdam wall clock; the window may wrap midnight). */
+export function inQuiet(at: Date, quiet: Quiet): boolean {
+	if (!quiet) return false;
+	const z = zoned(at);
+	const t = z.h * 60 + z.min;
+	return quiet.from < quiet.to ? t >= quiet.from && t < quiet.to : t >= quiet.from || t < quiet.to;
+}