adding some initial timezone handling

app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/EventActivity.kt

@@ -313,6 +313,7 @@ class EventActivity : SimpleActivity() {
         checkReminderTexts()
         updateStartTexts()
         updateEndTexts()
+        updateTimeZoneText()
         updateAttendeesVisibility()
     }
 
@@ -1054,6 +1055,10 @@ class EventActivity : SimpleActivity() {
         checkStartEndValidity()
     }
 
+    private fun updateTimeZoneText() {
+        event_timezone.text = mEvent.getTimeZoneString()
+    }
+
     private fun checkStartEndValidity() {
         val textColor = if (mEventStartDateTime.isAfter(mEventEndDateTime)) resources.getColor(R.color.red_text) else config.textColor
         event_end_date.setTextColor(textColor)

app/src/main/kotlin/com/simplemobiletools/calendar/pro/helpers/Constants.kt

@@ -1,5 +1,7 @@
 package com.simplemobiletools.calendar.pro.helpers
 
+import com.simplemobiletools.calendar.pro.models.MyTimeZone
+
 const val LOW_ALPHA = .3f
 const val MEDIUM_ALPHA = .6f
 const val STORED_LOCALLY_ONLY = 0
@@ -157,3 +159,10 @@ const val REMINDER_NOTIFICATION = 0
 const val REMINDER_EMAIL = 1
 
 fun getNowSeconds() = System.currentTimeMillis() / 1000L
+
+// timezones fetched from https://www.joda.org/joda-time/timezones.html
+fun getAllTimeZones() = arrayListOf(
+        MyTimeZone(1, "GMT-11:00", "Pacific/Midway"),
+        MyTimeZone(2, "GMT-11:00", "Pacific/Niue"),
+        MyTimeZone(3, "GMT-11:00", "Pacific/Pago_Pago")
+)

app/src/main/kotlin/com/simplemobiletools/calendar/pro/models/Event.kt

@@ -9,6 +9,7 @@ import com.simplemobiletools.calendar.pro.extensions.seconds
 import com.simplemobiletools.calendar.pro.helpers.*
 import com.simplemobiletools.commons.extensions.addBitIf
 import org.joda.time.DateTime
+import org.joda.time.DateTimeZone
 import java.io.Serializable
 
 @Entity(tableName = "events", indices = [(Index(value = ["id"], unique = true))])
@@ -177,4 +178,12 @@ data class Event(
         }
 
     var color: Int = 0
+
+    fun getTimeZoneString(): String {
+        return if (timeZone.isNotEmpty() && getAllTimeZones().map { it.zoneName }.contains(timeZone)) {
+            timeZone
+        } else {
+            DateTimeZone.getDefault().id
+        }
+    }
 }

app/src/main/kotlin/com/simplemobiletools/calendar/pro/models/MyTimeZone.kt

@@ -0,0 +1,3 @@
+package com.simplemobiletools.calendar.pro.models
+
+data class MyTimeZone(val id: Int, var title: String, val zoneName: String)