iPhone: Convert date string to a relative time stamp

Question

I\'ve got a timestamp as a string like:

Thu, 21 May 09 19:10:09 -0700

and I\'d like to convert it to a relative time stamp like

Answer 1

Use the NSDate class:

timeIntervalSinceDate

returns the interval in seconds.

Quick exercise to implement this in objective-c:

1. Get time "now" NSDate
2. Get the NSDate you wish to compare with
3. Get the interval in seconds using timeIntervalSinceDate

Then implement this pseudo code:

if (x < 60) // x seconds ago

else if( x/60 < 60) // floor(x/60) minutes ago

else if (x/(60*60) < 24) // floor(x/(60*60) hours ago

else if (x/(24*60*60) < 7) // floor(x(24*60*60) days ago

and so on...

then you need to decide whether a month is 30,31 or 28 days. Keep it simple - pick 30.

There might be a better way, but its 2am and this is the first thing that came to mind...