Win32 - localtime function is an hour out on one of my machines?

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Possibly more of an OS question.. but here goes.

I'm creating backups based on the current time, using localtime to convert to the user date / time

time_t          rawtime;
     struct tm      *timeinfo;
     char            timestring [TIME_STRING_LENGTH+1];

     time (&rawtime);
     timeinfo = localtime (&rawtime);

     strftime (timestring,TIME_STRING_LENGTH,"%Y_%m_%d_%H_%M_%S",timeinfo);

MSDN -

C#

Convert a time value and correct for the local time zone

I've deployed this to a number of our test boxes - just one gets it wrong - I'm in the UK, it's BST today (GMT+1). One machine (Win7_64) appears to output GMT - one hour behind what's on the clock in the systray. Clock settings appear to be consistent across all my machines.

Is there another API I should be using?

Thanks

What I have tried:

gmtime, msdn, google ......................

Posted 22-Sep-16 22:44pm

Simon Langdon

Updated 23-Sep-16 1:02am

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Richard MacCutchan 23-Sep-16 5:00am

Just tried your code here (Woking) on Win 10 64 bit, and the values are all correct. Is there something odd about that system?

Simon Langdon 23-Sep-16 5:20am

cheers - everyone here I've asked to run it says it works fine, Win10, Win8, Win7, Server 2012. Just one machine then }-(

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Simon Langdon · Accepted Answer · 2016-09-23T01:02:00

Solution 1

I've found a different function that seems to do what I expect :-)

SYSTEMTIME st;

GetLocalTime(&st);

CString time2;

time2.Format(TEXT ("%d_%d_%d_%d_%d_%d"), st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);

Posted 23-Sep-16 1:02am

Simon Langdon

Updated 23-Sep-16 1:03am

Comments

Richard MacCutchan 23-Sep-16 7:41am

That is still very weird.

Richard MacCutchan 23-Sep-16 7:45am

Just checked again and both methods produce the same (correct) time.

Simon Langdon 26-Sep-16 5:24am

Yes I discovered another machine on site that was also producing the wrong time - that was Win8 / 64. It doesn't seem OS specific. Someone suggested the bios clock, but that was consistent with Windows and other machines.