IAR <time.h>, localtime, mktime
I am using DLib for your IAR compiler and would like to convert UTC timestamp to local timestamp.
I am hosted in Germany, so my implementation for the __getzone method is as follows:
char const * __getzone() {
return ":GMT+1:GMT+2:0100:(1980)032502+0:102503+0";
}
I wrote some test codes:
time_t ts = 1509238797L;//29.10.2017-02:59:57 3 seconds before dst
struct tm* pre = localtime(&ts);
time_t after = ts + 5L;//wait 5 seconds -> 29.10.2017-02:00:02
struct tm* post = localtime(&after);
The variable "pre" is good, but the variable "post" contains the value: 10/29/2017 - 03:00: 02, but it should be 2017/10/29 - 02: 00: 02.
I've debugged the code in Visual Studio and everything seems to work there. Did I miss something?
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1 answer
I think I found it myself. Right line: GMT + 1: GMT + 2: 0100: 032502 + 0: 102502 + 0
DST starts at 2 pm and ends at 2 pm and I don't think I was thinking at 3 pm. I think the api description is not quite perfect.
Some tests for checking DST transitions:
//Forward
time_t ts = 1490489997L;//26.03.2017-01:59:57 3 seconds before dst
struct tm* pre = localtime(&ts);
time_t after = ts + 5L;//wait 5 seconds -> 26.03.2017-03:00:02
struct tm* post = localtime(&after);
//Backward
time_t ts = 1509238797L;//29.10.2017-02:59:57 3 seconds before dst
struct tm* pre = localtime(&ts);
time_t after = ts + 5L;//wait 5 seconds -> 29.10.2017-02:00:02
struct tm* post = localtime(&after);
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