diff --git a/core/src/main/kotlin/ai/neuon/utility/time/Instant.kt b/core/src/main/kotlin/ai/neuon/utility/time/Instant.kt
index 68d52ea..f842fc9 100644
--- a/core/src/main/kotlin/ai/neuon/utility/time/Instant.kt
+++ b/core/src/main/kotlin/ai/neuon/utility/time/Instant.kt
@@ -2,5 +2,21 @@
 
 package ai.neuon.utility.time
 
+import java.time.ZoneId
 import kotlin.time.ExperimentalTime
+import kotlin.time.Instant
+import java.time.Instant as JavaInstant
 
+fun Instant.atStartOfMonth(timezone: ZoneId): Instant {
+    val javaInstant = JavaInstant.ofEpochSecond(epochSeconds, nanosecondsOfSecond.toLong())
+    val zoned = javaInstant.atZone(timezone)
+        .withDayOfMonth(1)
+        .withHour(0).withMinute(0).withSecond(0).withNano(0)
+    return Instant.fromEpochSeconds(zoned.toEpochSecond(), zoned.nano)
+}
+
+fun Instant.plusMonths(months: Long, timezone: ZoneId): Instant {
+    val javaInstant = JavaInstant.ofEpochSecond(epochSeconds, nanosecondsOfSecond.toLong())
+    val zoned = javaInstant.atZone(timezone).plusMonths(months)
+    return Instant.fromEpochSeconds(zoned.toEpochSecond(), zoned.nano)
+}