Add new date time utility function to receive difference for a date i…

…n days.

graylog2-web-interface/src/util/DateTime.test.ts

@@ -19,14 +19,15 @@
 import moment from 'moment-timezone';
 
 import {
-  relativeDifference,
-  formatAsBrowserTime,
-  adjustFormat,
-  toUTCFromTz,
   DATE_TIME_FORMATS,
+  adjustFormat,
+  formatAsBrowserTime,
   getBrowserTimezone,
   parseFromIsoString,
+  relativeDifference,
+  relativeDifferenceDays,
   toDateObject,
+  toUTCFromTz,
 } from 'util/DateTime';
 
 const mockRootTimeZone = 'America/Chicago';
@@ -170,6 +171,12 @@ describe('DateTime utils', () => {
     });
   });
 
+  describe('relativeDifferenceDays', () => {
+    it('should return relative difference for time in days', () => {
+      expect(relativeDifferenceDays('2019-01-01T10:00:00.000Z')).toBe(364);
+    });
+  });
+
   describe('toUTCFromTz', () => {
     it('should transform time to UTC based on defined tz', () => {
       expect(toUTCFromTz('2020-01-01T10:00:00.000', moscowTZ).toISOString()).toEqual('2020-01-01T07:00:00.000Z');

graylog2-web-interface/src/util/DateTime.ts

@@ -104,6 +104,16 @@ export const relativeDifference = (dateTime: DateTime) => {
   return validateDateTime(dateObject, dateTime).fromNow();
 };
 
+/**
+ * Returns the time, relative to the provided date time, in days.
+ */
+export const relativeDifferenceDays = (dateTime: DateTime) => {
+  const eventDateObject = toDateObject(dateTime);
+  const todayDateObject = toDateObject(new Date());
+
+  return todayDateObject.diff(eventDateObject, 'days');
+};
+
 /**
  * Validate if the provided time has a supported format.
  */