diff --git a/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/CalendarDateSlotEvent.kt b/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/CalendarDateSlotEvent.kt
index 2bd1eb054..a41cfcf89 100644
--- a/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/CalendarDateSlotEvent.kt
+++ b/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/CalendarDateSlotEvent.kt
@@ -86,7 +86,7 @@ class CalendarDateSlotEvent(
             initializer: TagArrayBuilder<CalendarDateSlotEvent>.() -> Unit = {},
         ) = eventTemplate(KIND, content, createdAt) {
             dTag(dTag)
-            title(title)
+            titleDay(title)
             startDate(start)
             end?.let { endDate(it) }
             alt(ALT)
diff --git a/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/CalendarTimeSlotEvent.kt b/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/CalendarTimeSlotEvent.kt
index a6898ae28..d96bba63c 100644
--- a/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/CalendarTimeSlotEvent.kt
+++ b/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/CalendarTimeSlotEvent.kt
@@ -93,7 +93,7 @@ class CalendarTimeSlotEvent(
             initializer: TagArrayBuilder<CalendarTimeSlotEvent>.() -> Unit = {},
         ) = eventTemplate(KIND, content, createdAt) {
             dTag(dTag)
-            title(title)
+            titleTime(title)
             startTimestamp(start)
             end?.let { endTimestamp(it) }
             startTzId?.let { startTzId(it) }
diff --git a/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/TagArrayBuilderExt.kt b/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/TagArrayBuilderExt.kt
index c23ef6813..c50a5ea2c 100644
--- a/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/TagArrayBuilderExt.kt
+++ b/quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip52Calendar/TagArrayBuilderExt.kt
@@ -32,7 +32,7 @@ import com.vitorpamplona.quartz.nip52Calendar.tags.RSVPStatusTag
 
 // CalendarDateSlotEvent builder extensions
 
-fun TagArrayBuilder<CalendarDateSlotEvent>.title(title: String) = addUnique(TitleTag.assemble(title))
+fun TagArrayBuilder<CalendarDateSlotEvent>.titleDay(title: String) = addUnique(TitleTag.assemble(title))
 
 fun TagArrayBuilder<CalendarDateSlotEvent>.startDate(date: String) = addUnique(arrayOf("start", date))
 
@@ -54,7 +54,7 @@ fun TagArrayBuilder<CalendarDateSlotEvent>.participants(ps: List<PTag>) = addAll
 
 // CalendarTimeSlotEvent builder extensions
 
-fun TagArrayBuilder<CalendarTimeSlotEvent>.title(title: String) = addUnique(TitleTag.assemble(title))
+fun TagArrayBuilder<CalendarTimeSlotEvent>.titleTime(title: String) = addUnique(TitleTag.assemble(title))
 
 fun TagArrayBuilder<CalendarTimeSlotEvent>.startTimestamp(timestamp: Long) = addUnique(arrayOf("start", timestamp.toString()))