Dr.Neil Degrasse Tyson on the Verge:
.. the bulk of the Androids get their time from GPS satellites.. The time keeping bases for the GPS satellites was defined upto 1982 and since 1982, 15 seconds have been added to civil time and that 15s is not included in the Andorid time keeping settings (because their getting their time directly from GPS), whereas the iPhone compensates for this and puts the 15s backs in…
You should watch the whole episode, Dr Neil is one of the most entertaining astro physicists on the planet.