Converting seconds to date

lucasromeiro · Joined: 27 Mar 2010 Posts: 167

Hello. I need to convert seconds date!
UTC to local time
day
month
year
hour
minute
second
Can someone help me?
I tried to use the time.c library, but could not. because of the error.
Can someone help me?

dyeatman · Joined: 06 Sep 2003 Posts: 1924 Location: Norman, OK

Did you include time.h before time.c?
It would help if you read the header in time.c

lucasromeiro · Joined: 27 Mar 2010 Posts: 167

dyeatman · Joined: 06 Sep 2003 Posts: 1924 Location: Norman, OK

It compiles just fine for me with both includes under 5.056
Please give your version and show your code from the start to where time.c is included...
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lucasromeiro · Joined: 27 Mar 2010 Posts: 167

lucasromeiro · Joined: 27 Mar 2010 Posts: 167

there is no other way to do what I want?

dyeatman · Joined: 06 Sep 2003 Posts: 1924 Location: Norman, OK

First of all, you have something wrong in your program so you need to resolve the issues not look for other solutions.

The message your getting now indicates you have a coding error before time.h, possibly in timestamp.c (BTW, what is this?)

Try moving string.h, time.h and time.c (in that order) up to right after the word //INCLUDES and above all the rest of the includes.

BTW, your utility includes stdio, time, string etc need to always come before the drivers...
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ezflyr · Joined: 25 Oct 2010 Posts: 1019 Location: Tewksbury, MA

Hi,

First, I agree with dyeatman that you need to understand, and solve, your current problem first before moving on.....

Having said that, I must say that this is an odd request! So, you are saying that you have a UTC time in seconds (Unix time?) that you need to convert to local time? Is that correct? What is the source of the Unix time? Can you show us a sample?

IOW, give us more background, and describe more fully what you are trying to do. That will better enable us to offer help and solutions! For example, I have a function that takes UTC time from a GPS receiver, and converts it to local time based on a user selectable UTC offset. Is that anything like you are trying to do?

John
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asmboy · Joined: 20 Nov 2007 Posts: 2128 Location: albany ny

International time standards - as opposed to absolute time reference sources

for french speakers TAI and UTC become UCT and IAT

So UTC ==UCT

Universal coordinated time

http://www.timeanddate.com/time/aboututc.html

and a nice entry here that explains key
reference time relationships.
including the GPS "19 second difference"

https://en.wikipedia.org/wiki/Coordinated_Universal_Time

poster needs to explain what he wants to do and post some code.

Ttelmah · Joined: 11 Mar 2010 Posts: 19348

Yes.

The first key point is though that the standard Unix time.c, ported to CCS, is supplied with CCS, and includes the code to convert date/time, to seconds UTC, and back. It works if used properly, and so he should get this working.

GPS to date/time, has the potential problem of leap seconds, but is relatively easy to fix provided you are prepared to input the offset (as ezflyr has said). He presumably just includes the leap value in his input (I too have had to do this, with you simply inputting the local timezone, and leap seconds).

Handling GPS leap seconds really is simplest handled by just inputting them. Problem is that they are unpredictable (the shift is changed by things like El Nino events), so there is no formula for these. My code stores the last value input, and uses this if it is not updated.