From 94cb850fa4ed67b76c2d90657864c2a7b3a5cb01 Mon Sep 17 00:00:00 2001
From: Jean-Luc Makiola <business@jeanlucmakiola.de>
Date: Wed, 23 Sep 2026 18:15:12 +0200
Subject: [PATCH] core-time: optional 12/24-hour override for formatTime and
 friends

---
 .../floret/time/DateTimeFormat.kt             | 25 ++++++++++++++-----
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/core-time/src/main/kotlin/de/jeanlucmakiola/floret/time/DateTimeFormat.kt b/core-time/src/main/kotlin/de/jeanlucmakiola/floret/time/DateTimeFormat.kt
index bb5367a..d7f2208 100644
--- a/core-time/src/main/kotlin/de/jeanlucmakiola/floret/time/DateTimeFormat.kt
+++ b/core-time/src/main/kotlin/de/jeanlucmakiola/floret/time/DateTimeFormat.kt
@@ -39,12 +39,25 @@ private fun Instant.atDisplayZone(allDay: Boolean) =
 fun Instant.formatDate(allDay: Boolean = false): String =
     atDisplayZone(allDay).format(dateFormatter)
 
-/** Short localized time, e.g. "14:30". */
-fun Instant.formatTime(): String = atSystemZone().format(timeFormatter)
+private val timeFormatter24: DateTimeFormatter = DateTimeFormatter.ofPattern("HH:mm")
+private val timeFormatter12: DateTimeFormatter = DateTimeFormatter.ofPattern("h:mm a")
+
+/**
+ * Short time, e.g. "14:30". [is24Hour] forces a 12- or 24-hour clock; null keeps
+ * the locale's own short pattern.
+ */
+fun Instant.formatTime(is24Hour: Boolean? = null): String {
+    val formatter = when (is24Hour) {
+        null -> timeFormatter
+        true -> timeFormatter24
+        false -> timeFormatter12.withLocale(Locale.getDefault())
+    }
+    return atSystemZone().format(formatter)
+}
 
 /** Date alone for all-day items, otherwise date + time. */
-fun Instant.formatDateTime(allDay: Boolean): String =
-    if (allDay) formatDate(allDay = true) else "${formatDate()} · ${formatTime()}"
+fun Instant.formatDateTime(allDay: Boolean, is24Hour: Boolean? = null): String =
+    if (allDay) formatDate(allDay = true) else "${formatDate()} · ${formatTime(is24Hour)}"
 
 // The locale's medium date pattern with the year token stripped, e.g. "20 Jun" /
 // "Jun 20" — derived from the pattern so day/month order still follows the locale.
@@ -62,11 +75,11 @@ private val dateNoYearFormatter: DateTimeFormatter = run {
  * current year, and the time is dropped when it carries no information (all-day
  * items, or a midnight time). Examples: "20 Jun", "20 Jun · 14:30", "20 Jun 2027".
  */
-fun Instant.formatDateTimeCompact(allDay: Boolean): String {
+fun Instant.formatDateTimeCompact(allDay: Boolean, is24Hour: Boolean? = null): String {
     val zdt = atDisplayZone(allDay)
     val datePart =
         if (zdt.year == LocalDate.now(ZoneId.systemDefault()).year) zdt.format(dateNoYearFormatter)
         else formatDate(allDay)
     return if (allDay || zdt.toLocalTime() == LocalTime.MIDNIGHT) datePart
-    else "$datePart · ${formatTime()}"
+    else "$datePart · ${formatTime(is24Hour)}"
 }