Dear Everyone,

I just found an interesting issue using mktm(). What I'm trying to do is
that I have a tm struct, convert it into seconds since 01/01/1980 with
mktime(), subtract 86400 seconds from it (one day), then convert it back to
tm with mktm(). The restulting struct contains the correct time of the day,
but an absolutely wrong date, some 3 years earlier. The interesting thing is
that when I convert the resulting tm into seconds again, it is the correct
value, 86400 less than the original one. mktm() works fine in other spots of
my program. I use an RCM4200 with Dynamic C 10.09. Any ideas?

Thanks in advance, Gusztav



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Gusztáv Gyõri wrote:

> Dear Everyone,
>
> I just found an interesting issue using mktm(). What I'm trying to do is
> that I have a tm struct, convert it into seconds since 01/01/1980 with
> mktime(), subtract 86400 seconds from it (one day), then convert it back to
> tm with mktm(). The restulting struct contains the correct time of the day,
> but an absolutely wrong date, some 3 years earlier. The interesting thing is
> that when I convert the resulting tm into seconds again, it is the correct
> value, 86400 less than the original one. mktm() works fine in other spots of
> my program. I use an RCM4200 with Dynamic C 10.09. Any ideas?
>
> Thanks in advance, Gusztav
>

Are you using long datatype; I think it has to be unsigned long type

so minus 86400UL

Tim S
------------------------------------



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The values in seconds are correct, so this should be no problem.

Gusztav
>
> Are you using long datatype; I think it has to be unsigned long type
>
> so minus 86400UL
>
> Tim S



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Gusztáv Gyõri wrote:

> The values in seconds are correct, so this should be no problem.
>
> Gusztav

I take you are not using Dynamic C since you think it is not an problem.

Tim S
------------------------------------



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:) Nice one, I had to try it, but didn't help. Ideas are still welcome.



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Weird… I haven’t got all the parts of this discussion, but just fount them
on the groups page…

Oh well.

I can’t say I’ve ever had any problems with these functions.

…..so what happens if you don’t subtract the a day’s worth of seconds?

Does converting a tm struct to seconds, then back to a tm struct work?

Also, have you looked at the seconds value, and done the maths yourself to
check what you’re getting out of your tm struct when it’s converted?

Maybe you could include definitions and actual code segments??

Julian Higginson

Bruttour International P/L

http://www.bruttour.com.au

Ph: +612 9987 1581

From: r...@yahoogroups.com [mailto:r...@yahoogroups.com] On
Behalf Of Gusztáv Gyori
Sent: Monday, 1 September 2008 9:22 PM
To: r...@yahoogroups.com
Subject: Re: [rabbit-semi] Re: Re: mktm() problems

:) Nice one, I had to try it, but didn't help. Ideas are still welcome.



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