How to get time_t value that is a week old

Hi there,
How to get a time_t (Unix Time) value that is a week old, month old, day old.

I am getting the current time as below.

time_t current_time;
time(&current_time);
cout << "Current Time: " << current_time << endl;

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ambuliAsked:
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ozoCommented:
current_time-7*24*60*60
current_time-30*24*60*60
current_time-24*60*60
If you need the exactly corresponding time of day across daylight saving changes, or the corresponding day of the month across month length changes, this may need to be modified
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ambuliAuthor Commented:
Thanks.  I was thinking of doing the same.  But, is there a better way to do this?
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ozoCommented:
Does "better" mean accounting for daylight saving changes and/or month length changes?
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ambuliAuthor Commented:
yes :-)
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evilrixSenior Software Engineer (Avast)Commented:
Why not create a TM struct with the time/date now and then subtract the number of days/months?
http://www.cplusplus.com/reference/ctime/tm/

Once you've done that you can turn it into a time_t using mktime
http://www.cplusplus.com/reference/ctime/mktime/

Alternatively, if you are using C++11 you can use the new Chrono library.
http://www.cplusplus.com/reference/chrono/
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ozoCommented:
struct tm t[1];
localtime_r(&current_time, t);

t[0].tm_mday-=7;
time_t weekOld=mktime(&t[0]);
cout << weekOld << endl;
t[0].tm_mday+=7;

t[0].tm_mon-=1;
time_t monthOld=mktime(&t[0]);
cout << monthOld << endl;
t[0].tm_mon+=1;

t[0].tm_mday-=1;
time_t dayOld=mktime(&t[0]);
cout << dayOld << endl;
t[0].tm_mday+=1;
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