diff --git a/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/Constants.kt b/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/Constants.kt
index 078dda6a5..287a437aa 100644
--- a/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/Constants.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/Constants.kt
@@ -84,6 +84,7 @@ val CATEGORIES = "CATEGORIES:"
 val STATUS = "STATUS:"
 val EXDATE = "EXDATE"
 val BYDAY = "BYDAY"
+val BYMONTHDAY = "BYMONTHDAY"
 
 val DISPLAY = "DISPLAY"
 val FREQ = "FREQ"
diff --git a/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsExporter.kt b/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsExporter.kt
index d84d2a60d..0a397a3c3 100644
--- a/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsExporter.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsExporter.kt
@@ -2,6 +2,8 @@ package com.simplemobiletools.calendar.helpers
 
 import com.simplemobiletools.calendar.activities.SimpleActivity
 import com.simplemobiletools.calendar.extensions.dbHelper
+import com.simplemobiletools.calendar.extensions.isXMonthlyRepetition
+import com.simplemobiletools.calendar.extensions.isXWeeklyRepetition
 import com.simplemobiletools.calendar.extensions.writeLn
 import com.simplemobiletools.calendar.helpers.IcsExporter.ExportResult.*
 import com.simplemobiletools.calendar.models.Event
@@ -103,11 +105,17 @@ class IcsExporter {
     }
 
     private fun getByDay(event: Event): String {
-        return if (event.repeatInterval == 0 || event.repeatInterval % WEEK != 0) {
-            ""
-        } else {
+        return if (event.repeatInterval.isXWeeklyRepetition()) {
             val days = getByDayString(event.repeatRule)
             ";$BYDAY=$days"
+        } else if (event.repeatInterval.isXMonthlyRepetition()) {
+            if (event.repeatRule == REPEAT_MONTH_LAST_DAY) {
+                ";$BYMONTHDAY=-1"
+            } else {
+                ""
+            }
+        } else {
+            ""
         }
     }
 
diff --git a/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsImporter.kt b/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsImporter.kt
index 924333244..b3714cf23 100644
--- a/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsImporter.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsImporter.kt
@@ -202,6 +202,8 @@ class IcsImporter {
                 if (value == WEEKLY) {
                     val start = Formatter.getDateTimeFromTS(curStart)
                     curRepeatRule = Math.pow(2.0, (start.dayOfWeek - 1).toDouble()).toInt()
+                } else if (value == MONTHLY) {
+                    curRepeatRule = REPEAT_MONTH_SAME_DAY
                 }
             } else if (key == COUNT) {
                 curRepeatLimit = -value.toInt()
@@ -211,6 +213,8 @@ class IcsImporter {
                 frequencySeconds *= value.toInt()
             } else if (key == BYDAY) {
                 handleRepeatRule(value)
+            } else if (key == BYMONTHDAY && value.toInt() == -1) {
+                curRepeatRule = REPEAT_MONTH_LAST_DAY
             }
         }
         return frequencySeconds