How to correctly read dates and times on Cellebrite UFED forensic reports
General information about the time
Everything is based on the meridian of Greenwich, in Great Britain, which is the starting point, the so-called meridian Zero, where zero is the longitude. It crosses the Astronomical Observatory located in the London suburb of the same name. All time zones have been calculated from here, for 137 years now. How?
Let’s start from the fact that the Earth is a sphere that takes 24 hours to complete one revolution on itself.
The rotation is equal to 360°, therefore, if we divide the degrees by the hours, we obtain 15°, i.e. the rotation that our planet completes in one hour.
For this, the world has been divided into 24 time zones.
For example, compared to GMT (Greenwich Mean Time), Italy is +1.
However, the time zone is measured in UTC which coincides with GMT except for infinitesimal approximations. Let’s briefly see the difference.
UTC (Universal Time Coordinated) is the Coordinated Universal Time passing through the Greenwich Observatory.
It represents the time measured with atomic clocks.
GMT is instead the time measured by astronomical observations.
Since January 1, 1972, the time zone is measured in UTC. We therefore have UTC+1, UTC+2, etc., as negative UTC-1, UTC-2, etc.
At this point, we can introduce the two concepts of solar time and summer time.
Solar time is none other than that marked by our reference time zone, the natural time of the sun to be precise.
Daylight saving time, on the other hand, involves moving the clock hands forward one hour. In essence, the purpose of summer time would be to take advantage of the hours of light, with consequent energy savings.
Although it is not a time zone, daylight saving time is an additional aspect to take into consideration.
In 1996, the EU, through the Law of 4 June 2010 n.96, in art.22 established that all EU countries have common dates for the beginning and end of summer time. Therefore, daylight saving time is introduced on the last Sunday in March at 01:00 UTC (02:00 Italian standard time), while standard time returns to effect on the last Sunday in October at 01:00 UTC (03:00 UTC). 00 Italian solar time).
The Italian time zone is, therefore, UTC+1 during solar time, while UTC+2 during summer time.
This means that if we find UTC+0 on the device and we are in solar time it will be UTC+1, if the time shown is for example 12.30 UTC+0, we will refer to 1.30 pm.
However, if this happens in the summer time period, it will be UTC+2, in this case if the time shown is for example 12.30, it will be 2.30.
Example:
| Device event reference | Real event value |
| Chat 23/12/2022 12.30 UTC+0 | 13.30 UTC+1 reale periodo ora solare |
| Chat 18/04/2022 12.30 UTC+0 | 14.30 UTC+2 reale periodo ora legale |
| Chat 12/06/2022 10.45 UTC+1 | 11.45 UTC+2 reale periodo ora legale |