About daylight savings time

[dongil]

I wonder about daylight savings time.

if I make a project in us, I have to consider about daylight savings time.

is there any configuration about it ?

in November, the time is back. so I think, it maybe make a some problem of wincc oa database manager.

I waiting answer.

[mkoller]

There's no need to worry about daylight saving time since the timestamp in WinCC_OA is internally always handled in UTC time.
It's just while _displaying_ when the UTC time is converted to a local time zone string representation.

[dongil]

Thanks reply Martin Koller.

when clocks are turned backward 1 hour , how can I know, it is second time ??

I think that it could be made duplicated data.

there is a function what it is managed day light saving time in the WinCC OA but, if you use third party database program. you should avoid to duplicated data.

[leoknipp]

Hello,

as Martin Koller has written WinCC OA is always using UTC time. The information if daylight saving needs to be used depends on the time zone settings.
There is a CTRL function daylightsaving() available in WinCC OA. Maybe this one can be used to solve the requirements.

When reading data from an external source you need to know if the time you get from this source is UTC or not and if daylight saving is set or not. Otherwise you cannot read data correctly.

Best Regards
Leopold Knipp
Senior Support Specialist