timothycomeau.com > writing

Chrome History

21 August 2012

In order to poke my brain to remember a site I figured out how to hack my Chrome History, and learned that Webkit doesn’t use Unixtime. Rather, it uses a timestamp of microseconds since 1 Jan 1601.

Thus to convert from Webkit Format to a generic Unixtime, divide by a million to get seconds, then subtract the number of seconds between 1 Jan 1970 and 1 Jan 1601 (11644473600).

In order to retrieve your Chrome history for analysis within a spreadsheet, (and if you’re using OS X) do the following:

1. Copy History file located at:

USER/Library/Application Support/Google/Chrome/Default/History

to working location, then:

2. open using SQLLite Browser
3. export table in question to CSV (in my case, urls)
4. open in Excel or Numbers
5. create column next to datetime you want to work with (last_visit_time)
6. apply this formula referencing the column in question:

=(CELL/1000000-11644473600)/60/60/24+”1 jan 1970″

7. Set the column to:

‘Custom’ = yyyy-mm-dd h:mm

Useful links:

Decoding Google Chrome Timestamps
Converting Unix Timestamps
Webkit Time

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Update 29 June 2013:

Reader Darlyn Perez wrote me to offer his Python script to convert a Webkit timestamp into a regular timestamp. As he says, “It basically does the same thing as the spreadsheet formula in your post.”

#!usr/bin/python

#Converts a Webkit timestamp (microseconds since Jan 1 1601) from keyboard input into a human-readable timestamp.
#Script by Darlyn Perez on 2013-06-29

import datetime
def date_from_webkit(webkit_timestamp):
    epoch_start = datetime.datetime(1601,1,1)
    delta = datetime.timedelta(microseconds=int(webkit_timestamp))
    print epoch_start + delta

inTime = int(raw_input('Enter a Webkit timestamp to convert:'))
date_from_webkit(inTime)