# Historic data in XY Chart not matching Historic data from system.tag.queryTagHistory **URL:** \ **Category:** Ignition Early Access\ **Created:** [July 29, 2019, 1:29pm UTC](https://forum.inductiveautomation.com/t/historic-data-in-xy-chart-not-matching-historic-data-from-system-tag-querytaghistory/26952 "2019-07-29T13:29:18Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![jlivingston](https://avatars.discourse-cdn.com/v4/letter/j/779978/32.png) [@jlivingston](https://forum.inductiveautomation.com/u/jlivingston)\ **Post date:** [July 29, 2019, 2:02pm UTC](https://forum.inductiveautomation.com/t/historic-data-in-xy-chart-not-matching-historic-data-from-system-tag-querytaghistory/26952/2 "2019-07-29T14:02:32Z")
There has been some research here on the forum about a similar situation: > [@Daylight Savings Time with queryTagHistory() function](http://forum.inductiveautomation.com/t/daylight-savings-time-with-querytaghistory-function/26554): > > I have a number of historical tags and when I plot them the axis (in a perspective XY chart) shows times that are 1 hour too early. I’m assuming it because of daylight saving, but I don’t know. For example, I turned my system on this morning around 10:16am but the graph shows around 9:16am [image] Here are the History settings for the tag And the database (MSSQL express) ‘t\_stamp’ values are an hour off [image] If I convert the t\_stamp value to a date as described [here](https://support.inductiveautomation.com/index.php?/Knowledgebase/Article/View/46/2/sqltag-historian-timestamps) using DA… I will not claim to be an expert, yet PGriffith has posted in the thread above- Mr. 'Witman' and he ( and others ) seem to have some great insights on the solution(s). I have been advised that it is also a good idea to inform folks about a more immediate alternative: you can go to: [https://support.inductiveautomation.com](https://support.inductiveautomation.com) Based on what you have said, I would check the thread, then look at the Knowledgebase article there which could be searched on with "Clock Drift detector", then look at the support policies. There is free non-priority e-mail support, and an account buys priority e-mail and/or voice support. Please let us know back here in the forum when/if the issue is solved. Many of us wish to know. Thanks! --- _[View the full topic](https://forum.inductiveautomation.com/t/historic-data-in-xy-chart-not-matching-historic-data-from-system-tag-querytaghistory/26952)._