diff --git a/components/calendar.js b/components/calendar.js
index 791654ae74834032d4b4560bcd0f51928744e955..6c4ec69987fd1d3eeab870da04e794486eb270c6 100644
--- a/components/calendar.js
+++ b/components/calendar.js
@@ -1,9 +1,9 @@
 import React, { Component } from 'react'
 import { CalendarList } from 'react-native-calendars'
-import {LocalDate} from 'js-joda'
+import { LocalDate } from 'js-joda'
 import { getBleedingDaysSortedByDate } from '../db'
 import cycleModule from '../lib/cycle'
-import {shadesOfRed} from '../styles/index'
+import { shadesOfRed, calendarTheme } from '../styles/index'
 import styles from '../styles/index'
 import nothingChanged from '../db/db-unchanged'
 
@@ -52,6 +52,9 @@ export default class CalendarView extends Component {
           )
         }
         markingType={'custom'}
+        // If firstDay=1 week starts from Monday. Note that dayNames and dayNamesShort should still start from Sunday.
+        firstDay={1}
+        theme={calendarTheme}
       />
     )
   }
diff --git a/styles/index.js b/styles/index.js
index c0dac87494e9941a9803e1bc4ab9bd4f8b550296..baa39373cfa4599348c8e1f61b215e8dd07dbcad 100644
--- a/styles/index.js
+++ b/styles/index.js
@@ -26,6 +26,16 @@ const defaultIndentation = 10
 const defaultTopMargin = 10
 const colorInActive = '#666666'
 
+export const calendarTheme = {
+  textDayFontFamily: textFont,
+  textMonthFontFamily: textFontBold,
+  textDayHeaderFontFamily: textFont,
+  textDayFontSize: regularSize,
+  textMonthFontSize: regularSize,
+  textDayHeaderFontSize: hintSize,
+  textSectionTitleColor: 'grey'
+}
+
 export default StyleSheet.create({
   appText: {
     color: 'black',