bigint to timestamp

[John Machin]

On Jan 29, 1:05 am, Jon Clements <jon... at googlemail.com> wrote:
> On Jan 28, 1:50 pm, Steve Holden <st... at holdenweb.com> wrote:
>
>
>
> > Shah Sultan Alam wrote:
> > > Hi Group,
> > > I have file with contents retrieved from mysql DB.
> > > which has a time field with type defined bigint(20)
> > > I want to parse that field into timestamp format(YYYY-MM-DD HH:MM:SS
> > > GMT) using python code.
> > > The value I found for that field is 212099016004150509
> > > Give me sample code that does the conversion.
>
> > Please?
>
> > Perhaps you could tell us what date and time 212099016004150509 is
> > supposed to represent? The classic format is "seconds since the Unix
> > epoch" but that isn't what this is:
>
> > >>> time.localtime(212099016004150509)
>
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in <module>
> > ValueError: timestamp out of range for platform time_t
>
> > Neither does it appear to be a MySQL TIME field, since the maximum value
> > for that would appear to be
>
> > >>> ((838*60)+59)*60+59
>
> > 3020399
>
> > So, just what is this field? What do the values mean?
>
> > regards
> >  Steve
> > --
> > Steve Holden        +1 571 484 6266   +1 800 494 3119
> > Holden Web LLC              http://www.holdenweb.com/
>
> Bit hard to guess without the actual date to compare to... and I'm a
> bit busy, but thought I'd throw this in the pool: I'm guessing it's a
> MySQL database that's had data put into it via a .NET application
> using the .NET DateTime (so a 20 byte int sounds about right IIRC),
> which is based on the number of ticks since Jan 1, 1.... I think that
> should end up around 2[18ish digits here...]...

Mmmm ... I thought it might be the MS format that's ticks since
1600-01-01T00-00-00 (proleptic Gregorian calendar) where ticks happen
10,000,000 times per second, but:

>>> x = 212099016004150509
>>> seconds = x / 10000000.0
>>> seconds
21209901600.415051
>>> days = seconds / 60. / 60. / 24.
>>> days
245484.97222702604
>>> years_approx = days / 365.25
>>> years_approx
672.10122444086528

which would make it in the year 2272.

Perhaps the OP could tell us what are the maximum and minimum non-zero
non-null values he can find, and what years those might belong to.
Also (very important) he might assure us that he is copying/pasting
those large numbers, not retyp[o]ing them.