How to change Domoticz graph sample time
Domoticz, by default, show 3 graphs: a daily graph with 1 sample every 5 minutes, a monthly graph and a yearly graph.
In some cases, 5 minutes is a very huge time if sensors data varies quickly: in these cases it's possible to reduce sampling interval for example to 1 minute (databases with sensors data will be much greater). In other cases, sensors data is very slow, so it's possible to set a longer sampling interval to save size and extend flash memory life.
To set a different sampling interval, it's possible to do as shown in the post https://www.domoticz.com/forum/viewtopic.php?f=47&t=10183&start=20#p129866
Edit the file DOMOTICZ_DIR/www/views/setup.html
Search for "shortlogtable" and add the following before the </table>-tag:
<tr> <td align="right" style="width:60px"><label><span data-i18n="Interval"></span>: </label></td> <td><select id="comboshortloginterval" name="ShortLogInterval" style="width:60px" class="combobox ui-corner-all"> <option value="1">1</option> <option value="5">5</option> <option value="10">10</option> <option value="15">15</option> </select>&nbsp; Minutes </tr>
Save it, delete your browser-cache and refresh your browser. I had problems with chrome keeping the old setup page even after deleting the cache, but using incognito mode worked to display the new page.
Finally, enter domoticz -> Setup -> Settings -> Log History and set the History value to 1 minute or longer sampling time.