Parsing “date” field of iPhone SMS file from backup

问题

While this isn't a programming question per se, it IS related.

So I'm trying to figure out how to parse the SMS DB that gets backed up from the iPhone. I'm looking at the "messages" table, specifically the "date" field. I noticed that the more recent messages are using a different numbering system to indicate the date/time. I've narrowed it down to the switch to iMessage, as I have a message sent at 1318470904, with a reply sent at 340164736. I know for a fact that these messages were sent less than an hour apart, yet they're indicating > 30 years' difference.

Anybody know how to accurately calculate the date using this newer system? Is it using a different epoch or is there some crazy math I need to do?

Edit: Recent messages are affected as well. Texts (green bubbles) are stored with the date set normally, and anything through iMessage (blue bubbles) is stored with the different date representation.

回答1:

Since the backup is exported to SQLite database format, here's how to convert the number to a real date in SQLite:

select
    datetime(date + strftime('%s', '2001-01-01 00:00:00'),
       'unixepoch', 'localtime') as date,
    *
from message

回答2:

It is in seconds since 1/1/2001 instead of the others which are Unix based off of 1/1/1970. So to convert it to say an Excel time your formula would be =Cell/(60*60*24) + "1/1/2001".

回答3:

I don't know about getting the correct date given two versions present, but when I did this today, I noticed the date column was not the standard unix time but a longer number with seemingly nine zeros at the end, like 444548608000000000. This is what I did to get the correct date:

select
    datetime(substr(date, 1, 9) + 978307200, 'unixepoch', 'localtime') as f_date,
    text
from message

回答4:

Apple uses Mac Absolute Time (MacTime). This is counted from 01-01-2001. The other timestamp you see is UnixTime. This starts from 01-01-1970.

You have to add 31 years to MacTime to get UnixTime. This is a PHP-snippit:

$macTime = $d['ZMESSAGEDATE']; // MacTime column (from Whatsapp)
$unixTime =  $macTime + 978307200;
echo date("Y-m-d H:i:s", $unixTime);

The time difference is calculated using this website: https://www.timeanddate.com/date/durationresult.html?d1=1&m1=1&y1=1970&d2=1&m2=1&y2=2001&h1=0&i1=0&s1=0&h2=0&i2=0&s2=0

回答5:

There may be another answer.

=Cell/(60*60*24) + "1/1/1970"

works with my current version of the iPhone/iOS => 4.3.3

回答6:

Fomurla with time of messages: =Cell/(60*60*24) + "1/1/2001 7:00"

回答7:

Since date in mac is calculated from 2001 and not 1970, we have to add some extra to this mac date.

978307200000 is equivalent to milliseconds until 2001-01-01

Also multiplying by 1000 is required to convert to milli-seconds.

macDate * 1000 + 978307200000

回答8:

Bohemian♦ is right, but there's a little typo in his answer:

use %S (capitals) instead of %s, since the time is represented in seconds since 2001 and not 1970!

Doc from https://www.sqlite.org/lang_datefunc.html

%s      seconds since 1970-01-01
%S      seconds: 00-59

select datetime(date + strftime('%S', '2001-01-01 00:00:00'), 'unixepoch', 'localtime') as date, * from message

来源：https://stackoverflow.com/questions/10746562/parsing-date-field-of-iphone-sms-file-from-backup

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iphone

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backup