<?xml version="1.0" encoding="UTF-8"?>
<helpdocument version="1.0">
<!--
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
-->

<meta>
  <topic id="textscalcguidecalc_datexml" indexer="include" status="PUBLISH">
    <title id="tit" xml-lang="en-US">Calculating With Dates and Times</title>
    <filename>/text/scalc/guide/calc_date.xhp</filename>
  </topic>
</meta>

<body>

<bookmark xml-lang="en-US" branch="index" id="bm_id3146120">
  <bookmark_value>dates; in cells</bookmark_value>
  <bookmark_value>times; in cells</bookmark_value>
  <bookmark_value>cells;date and time formats</bookmark_value>
  <bookmark_value>current date and time values</bookmark_value>
</bookmark>


<h1 id="hd_id3146120"><variable id="calc_date"><link href="text/scalc/guide/calc_date.xhp">Calculating With Dates and Times</link></variable></h1>
<paragraph id="par_id3154320" role="paragraph" xml-lang="en-US">In $[officename] Calc, you can perform calculations with current date and time values. As an example, to find out exactly how old you are in seconds or hours, follow the following steps:</paragraph>

<list type="ordered">
  <listitem>
    <paragraph id="par_id3150750" role="listitem" xml-lang="en-US">In a spreadsheet, enter your birthday in cell A1.</paragraph>
  </listitem>
  <listitem>
    <paragraph id="par_id3145642" role="listitem" xml-lang="en-US">Enter the following formula in cell A3: <item type="literal">=NOW()-A1</item></paragraph>
  </listitem>
  <listitem>
    <paragraph id="par_id3149020" role="listitem" xml-lang="en-US">After pressing the Enter key you will see the result in date format. Since the result should show the difference between two dates as a number of days, you must format cell A3 as a number.</paragraph>
  </listitem>
  <listitem>
    <paragraph id="par_id3155335" role="listitem" xml-lang="en-US">Place the cursor in cell A3, right-click to open a context menu and choose <emph>Format Cells</emph>.</paragraph>
  </listitem>
  <listitem>
    <paragraph id="par_id3147343" role="listitem" xml-lang="en-US">The <item type="menuitem">Format Cells</item> dialog appears. On the <item type="menuitem">Numbers</item> tab, the "Number" category will appear already highlighted. The format is set to "General", which causes the result of a calculation containing date entries to be displayed as a date. To display the result as a number, set the number format to "-1,234" and close the dialog with the <item type="menuitem">OK</item> button.</paragraph>
  </listitem>
  <listitem>
    <paragraph id="par_id3147001" role="listitem" xml-lang="en-US">The number of days between today's date and the specified date is displayed in cell A3.</paragraph>
  </listitem>
  <listitem>
    <paragraph id="par_id3150304" role="listitem" xml-lang="en-US">Experiment with some additional formulas: in A4 enter =A3*24 to calculate the hours, in A5 enter =A4*60 for the minutes, and in A6 enter =A5*60 for seconds. Press the Enter key after each formula.</paragraph>
  </listitem>
</list>
<paragraph id="par_id3149207" role="paragraph" xml-lang="en-US">The time since your date of birth will be calculated and displayed in the various units. The values are calculated as of the exact moment when you entered the last formula and pressed the Enter key. This value is not automatically updated, although "Now" continuously changes. In the <emph>Data</emph> menu, the menu item <emph>Calculate - AutoCalculate</emph> is normally active; however, automatic calculation does not apply to the function NOW. This ensures that your computer is not solely occupied with updating the sheet.</paragraph>

<section id="relatedtopics">
<embed href="text/scalc/guide/calc_timevalues.xhp#calc_timevalues"/>
</section>
</body>

</helpdocument>