What is the logic behind the timer of the Sojourner Badge?

Does the 24 hours timer start:

when you hack a portal on a particular day

does it use the calendar days and check if you did hack a portal on a particular day

does it simply use a fixed international timezone to calculate the 24 hour cycle

does it use the agent's hacking cell's timezone to start it?

If it's the calendar days method than the explanation of the badge would be a little bit misguided because you could hack a portal on 00:01 on Saturday and then hack another one on 23:59 on Sunday and it would be practically two days between two hacks.

If it's based on the agent's last hack for a particular day then the explanation still would be problematic?

The third option would be a little bit unfair (or timezone racist) for the rest of the world.

The last option (the cell's timezone) would/could be both unfair for travellers and/or non-travellers.

Does anyone know any details about it?

Solution 1:

NIA has issued an explanation yesterday on the inner workings of the Sojourner Badge.

Greetings Agents, there have been some questions on how the Sojourner medal works, so we decided to create a quick overview:

The medal tracks the longest streak of consecutive 24 hour periods in which you have hacked a Portal.

To keep this streak active, you must hack at least one Portal every 24 hours. If you hack at 10:00 AM one day, then you’ll need to do a hack by 10:00 AM the next day to keep the streak alive.

The 24 hour counter starts over every time you hack a Portal. If you hack at 10:00 AM, then again at 3:00 PM, you have until 3:00 PM the following day to hack again.

You may hack any Portal - it does not have to be the same Portal every time.

The stat shown as 'Consecutive Days Hacking' reflects your longest streak, not necessarily your current count (unless they are the same)

Solution 2:

Just to rephrase Niantic's official statement: this badge is like a rocket in time. Its petrol tank can only last for 24h, every hack you do fills it up completely. If you don't fill up for more than 24h the rocket crashes, and you have to restart again. The badge counter displays the longest distance in days your rocket has ever travelled.

Solution 3:

Max 36 hours, any portal, only successful hacks count

NOTE: These "rules" are not officially supported and may change at any time!

The only rule that is confirmed by Niantic is "max 24 hours per hack", although they have admitted there is a little bit of grace, but they never confirmed what that grace is.

I just did some testing on this, and the rules appears to be as follows:

You gain Sojourner medals for achieving a Hack Steak of 15, 30, 60, 180 and 360 days
Hacking on any portal counts
Only successful hacks count; failures due to full inventory does not count
Max 36 hours between hacks to maintain the Hack Streak

So this is the series of hacks I did, and the corresponding Hack Streak counter

Sunday, 20:12, 0 days
Monday
Tuesday, 08:10, 1 day
Wednesday, 20:08, 2 days
Thursday
Friday, 08:06, 4 days
Saturday, 20:04, 5 days
Sunday
Monday, 08:02, 7 days
Tuesday, 19:00, mistaken failed hack (inventory was full), 7 days (should have been 8)
Tuesday, 20:04, successful hack, 0 days

It might be worth noting that the Hack Streak counter said 8 days in the seconds just before the Tuesday 20:04 hack, and was then 0 directly after.

Notes on the Hack Streak counter

The Hack Streak counter is unreliable. It can say the Hack Streak is still on when it has in fact been reset
The time of day of the very first hack only tells when the hack streak counter will tick over after on a successful hack
The tick-over time is UTC, so if you started at 13:00 standard time, it will tick over on 14:00 in daylight saving time
The counter may tick over despite you not having hacked for that period, so you cannot use that as an indicator to recall if you have hacked successfully recently or not