store current time offset at inserting/updating event

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

@@ -452,6 +452,7 @@ class EventActivity : SimpleActivity(), DBHelper.EventUpdateListener {
             repeatLimit = if (repeatInterval == 0) 0 else mRepeatLimit
             repeatRule = mRepeatRule
             eventType = mEventTypeId
+            offset = getCurrentOffset()
         }
 
         if (mEvent.id == 0) {

app/src/main/kotlin/com/simplemobiletools/calendar/extensions/Context.kt

@@ -16,6 +16,7 @@ import android.support.v7.app.NotificationCompat
 import com.simplemobiletools.calendar.R
 import com.simplemobiletools.calendar.activities.EventActivity
 import com.simplemobiletools.calendar.helpers.*
+import com.simplemobiletools.calendar.helpers.Formatter
 import com.simplemobiletools.calendar.models.Event
 import com.simplemobiletools.calendar.receivers.NotificationReceiver
 import com.simplemobiletools.calendar.services.SnoozeService
@@ -24,6 +25,8 @@ import com.simplemobiletools.commons.extensions.isKitkatPlus
 import com.simplemobiletools.commons.extensions.isLollipopPlus
 import org.joda.time.DateTime
 import org.joda.time.DateTimeZone
+import java.text.SimpleDateFormat
+import java.util.*
 
 fun Context.updateWidgets() {
     val widgetsCnt = AppWidgetManager.getInstance(this).getAppWidgetIds(ComponentName(this, MyWidgetMonthlyProvider::class.java))
@@ -220,6 +223,8 @@ fun Context.launchNewEventIntent(startNewTask: Boolean = false, today: Boolean =
 
 fun Context.getNewEventTimestampFromCode(dayCode: String) = Formatter.getLocalDateTimeFromCode(dayCode).withTime(13, 0, 0, 0).seconds()
 
+fun Context.getCurrentOffset() = SimpleDateFormat("Z", Locale.getDefault()).format(Date())
+
 val Context.config: Config get() = Config.newInstance(this)
 
 val Context.dbHelper: DBHelper get() = DBHelper.newInstance(this)

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/DBHelper.kt

@@ -204,6 +204,7 @@ class DBHelper private constructor(val context: Context) : SQLiteOpenHelper(cont
             put(COL_FLAGS, event.flags)
             put(COL_EVENT_TYPE, event.eventType)
             put(COL_PARENT_EVENT_ID, 0)
+            put(COL_OFFSET, event.offset)
         }
     }
 
@@ -537,7 +538,7 @@ class DBHelper private constructor(val context: Context) : SQLiteOpenHelper(cont
 
     private val allColumns: Array<String>
         get() = arrayOf("$MAIN_TABLE_NAME.$COL_ID", COL_START_TS, COL_END_TS, COL_TITLE, COL_DESCRIPTION, COL_REMINDER_MINUTES, COL_REMINDER_MINUTES_2,
-                COL_REMINDER_MINUTES_3, COL_REPEAT_INTERVAL, COL_REPEAT_RULE, COL_IMPORT_ID, COL_FLAGS, COL_REPEAT_LIMIT, COL_EVENT_TYPE)
+                COL_REMINDER_MINUTES_3, COL_REPEAT_INTERVAL, COL_REPEAT_RULE, COL_IMPORT_ID, COL_FLAGS, COL_REPEAT_LIMIT, COL_EVENT_TYPE, COL_OFFSET)
 
     private fun fillEvents(cursor: Cursor?): List<Event> {
         val events = ArrayList<Event>()
@@ -558,6 +559,7 @@ class DBHelper private constructor(val context: Context) : SQLiteOpenHelper(cont
                     val flags = cursor.getIntValue(COL_FLAGS)
                     val repeatLimit = cursor.getIntValue(COL_REPEAT_LIMIT)
                     val eventType = cursor.getIntValue(COL_EVENT_TYPE)
+                    val offset = cursor.getStringValue(COL_OFFSET)
 
                     val ignoreEventOccurrences = if (repeatInterval != 0) {
                         getIgnoredOccurrences(id)
@@ -570,7 +572,7 @@ class DBHelper private constructor(val context: Context) : SQLiteOpenHelper(cont
                     }
 
                     val event = Event(id, startTS, endTS, title, description, reminder1Minutes, reminder2Minutes, reminder3Minutes,
-                            repeatInterval, importId, flags, repeatLimit, repeatRule, eventType, ignoreEventOccurrences)
+                            repeatInterval, importId, flags, repeatLimit, repeatRule, eventType, ignoreEventOccurrences, offset)
                     events.add(event)
                 } while (cursor.moveToNext())
             }

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

@@ -10,7 +10,7 @@ import java.util.*
 data class Event(var id: Int = 0, var startTS: Int = 0, var endTS: Int = 0, var title: String = "", var description: String = "",
                  var reminder1Minutes: Int = -1, var reminder2Minutes: Int = -1, var reminder3Minutes: Int = -1, var repeatInterval: Int = 0,
                  var importId: String? = "", var flags: Int = 0, var repeatLimit: Int = 0, var repeatRule: Int = 0,
-                 var eventType: Int = DBHelper.REGULAR_EVENT_TYPE_ID, var ignoreEventOccurrences: ArrayList<Int> = ArrayList()) : Serializable {
+                 var eventType: Int = DBHelper.REGULAR_EVENT_TYPE_ID, var ignoreEventOccurrences: ArrayList<Int> = ArrayList(), var offset: String = "") : Serializable {
 
     companion object {
         private val serialVersionUID = -32456795132345616L