To me it appears that ScratchDays give a value in timezone UTC+1.

Is this the same for everyone?

I understand that it doesn't actually matter which timezone the result is in as long as it is the same for everyone.

But, why UTC+1? There are a number of more logical timezones, e.g. UTC, local time at MIT, EST…

Hmm…I don't get what are scratch days. Did you get that sense? I don't have any ideas…

alanturing, are you by any chance in CET (UTC+1)? There was some talk about issues with the scratch time block and I understood that it wasn't actually universal but based on computer time.

No, as you might gather from the name (alanturing) I'm based in the UK so my local time is currently UTC.

I have tried this on Ubuntu (11.10/12.04) and Windows (XP/7) and still get the same result - but all the PCs were I must admit set to “Europe/London” as their time zone.

Are you saying that “Scratch Days” is actually returning something like “local time + permanent daylight saving/summer time”?

For timestamping cloud variables it's important that one of the times available is a “universal time” rather than a “local time”, so I hope this is on a “to do” list if necessary?

Cheers

Well, there was a thread about the block's inconsistency but I'm not sure as to whether it's been fixed.
i agree with you about the need for a universal timestamp!

LS97
Well, there was a thread about the block's inconsistency but I'm not sure as to whether it's been fixed.
i agree with you about the need for a universal timestamp!

gmt would probably be best, so youcould adjust it for certain time zones easily

I finally got the chance to change the timezone on one my PCs - the Ubuntu 12.04 one - I changed it to Auckland, New Zealand for maximum obvious effect - and even after this the Scratch Days value was still UTC+1, so maybe it does do what is intended.

I calculated when day zero was and it turned out to be May 15, 2007 - at which time Daylight Saving/Summer Time would be operating in the UK.

So, I think I can see what happened, this date was decided on as the Scratch birthday and someone decided to start the clock at midnight in the UK assuming that the UK would be at UTC - but due to Daylight Saving/Summer Time the UK was operating at UTC+1 on this date, hence the confusion.

I worked in the satellite telecom industry for a few years and we found that the only way to set a PC clock to UTC and make sure that it stayed at UTC was to tell the PC that it was in the Africa/Casablanca timezone…

Mr Turing! I'd thought we'd lost you. It is an honor to have you posting here, and thanks for creating my job!

Anyhow - this is a good glitch to catch, I'll file it, and we should be able to patch it up. Thanks!

alanturing
To me it appears that ScratchDays give a value in timezone UTC+1.
Is this the same for everyone?

(I think you're right about the time being off by an hour. Funny, it was correct when I tested it this past summer! :-). Will fix.)

Yes, at any given moment the ScratchDay block reports the same for everyone, no matter where they are or whether their local clocks are on daylight savings or not.

The ScratchDays block reports the elapsed time since the start of May 15, 2007 in UTC (Greenwich Mean Time). Since it is based on UTC, ScratchDays does not change with daylight savings time and it does not depend on what time zone the computer is in. ScratchDays gives you a way to record and compare “universal” times. For example, you might record the times that people ran your Scratch project (in a persistent cloud list), then later create a graph showing visits over time. It doesn't matter if the users who run your project are in the UK or Korea, they all use the same “ScratchDays” clock. If you got enough visitors, you'd probably see a 24 hour cycle in the graph as the “daytime” hours move around the globe.

Incidentally, while the units of ScratchDays are days (duh!), the resolution is seconds, so you can record when something happens to the nearest second. You could create a clock or calendar using the ScratchDays block. Or, if you note the ScratchDays value when the sun is highest in the sky, you could even compute your longitude the same way the early sailors did it.

bump

Socialix wrote:

bump

not cool, this was like, a normal old topic and stuff.

twogadugary wrote:

Socialix wrote:

bump

not cool, this was like, a normal old topic and stuff.

but i want scratchdays back

Socialix wrote:

bump

dOn'T nEcRoPoSt PlEaSe D:

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