работа с датами в sqllite

http://pleac.sourceforge.net/pleac_python/datesandtimes.html

http://www.opennet.ru/base/dev/sqlite_tut.txt.html

Other Date and Time Commands

   If you look in the sqlite3 source file "./src/date.c", you will see
   that datetime takes other options. For example, to get the localtime,
   plus 3.5 seconds, plus 10 minutes, you would execute the following
   command:

        sqlite> select datetime('now','localtime','+3.5 seconds','+10 minutes');
        2004-11-07 15:42:26


   It is also possible to get the weekday where 0 = Sunday, 1 = Monday, 2
   = Tuesday ... 6 = Saturday.

         sqlite> select datetime('now','localtime','+3.5 seconds','weekday 2');
         2004-11-09 15:36:51


   The complete list of options, or modifiers as they are called in this
   file, are as follows:

         NNN days
         NNN hours
         NNN minutes
         NNN.NNNN seconds
         NNN months
         NNN years
         start of month
         start of year
         start of week
         start of day
         weekday N
         unixepoch
         localtime
         utc


   In addition, there is the "strftime" function, which will take a
   timestring, and convert it to the specified format, with the
   modifications. Here is the format for this function:
 strftime( FORMAT, TIMESTRING, MOD, MOD, ...)         ** 
 Return a string described by FORMAT. Conversions as follows:         ** 
 %d day of month 
 %f ** fractional seconds SS.SSS 
 %H hour 00-24 
 %j day of year 000-366 
 %J ** Julian day number 
 %m month 01-12 
 %M minute 00-59 
 %s seconds since 1970-01-01 
 %S seconds 00-59 
 %w day of week 0-6 sunday==0 
 %W week of year 00-53 
 %Y year 0000-9999     Below is an example.          sqlite> select strftime("%m-%d-%Y %H:%M:%S %s %w %W",'now','localtime');         11-07-2004 16:23:15 1099844595 0 44