# Daylight Savings Time and HOYS

**URL:** <https://discourse.ladybug.tools/t/daylight-savings-time-and-hoys/7204>\
**Category:** ladybug\
**Created:** [September 19, 2019, 2:46am UTC](https://discourse.ladybug.tools/t/daylight-savings-time-and-hoys/7204 "2019-09-19T02:46:50Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![PaulWintour](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/paulwintour/32/5083_2.png) [@PaulWintour](https://discourse.ladybug.tools/u/PaulWintour)\
**Post date:** [September 19, 2019, 2:46am UTC](https://discourse.ladybug.tools/t/daylight-savings-time-and-hoys/7204/1 "2019-09-19T02:46:50Z")

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Hi

I am creating views from the sun in Dynamo. I am trying to modify it so that it incorporates DST. There is a useful node called ‘DateTime.IsDaylightSavingsTime’. Not sure what database it is referring to, but it seems accurate for my location. My question is - if I know which dates included/excluded DST, is it as simple as **adding** an additional 1 hour to the HOYS for that particular date? I believe it is additional because the clocks move forward at the commencement of DST, correct?

@devang @mostapha

 ![image](https://discourse.ladybug.tools/uploads/default/original/2X/6/62ae05d057764c00addf7fe22e0487ba1165fbe5.png)

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<div class="post-metadata">

**Author:** ![PaulWintour](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/paulwintour/32/5083_2.png) [@PaulWintour](https://discourse.ladybug.tools/u/PaulWintour)\
**Post date:** [September 24, 2019, 2:52am UTC](https://discourse.ladybug.tools/t/daylight-savings-time-and-hoys/7204/2 "2019-09-24T02:52:10Z")

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@mostapha @devang @chris any thoughts?

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<div class="post-metadata">

**Author:** ![PaulWintour](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/paulwintour/32/5083_2.png) [@PaulWintour](https://discourse.ladybug.tools/u/PaulWintour)\
**Post date:** [October 8, 2019, 6:06am UTC](https://discourse.ladybug.tools/t/daylight-savings-time-and-hoys/7204/3 "2019-10-08T06:06:42Z")

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FYI the ‘DateTime.IsDaylightSavingsTime’ node uses the [Windows settings](https://forum.dynamobim.com/t/is-daylight-savings-bug/41097/6) to determine DST which is not ideal. This has been flagged with the Dynamo team.

@mostapha @chris is my assumption correct about DST and HOY ?