Chapter 8. Date, Time, and Time Zone

• The very moment of month end is 23 hours 59 minutes 59.99 seconds because the PostgreSQL function MonthEnd() created by PostERP returns time values with precision 0.01 second.

  • Next example uses function MonthEnd(), hence 2012-8-1 23:59:59.991+8 is outside of time range:

    SELECT f2 FROM t52 WHERE f2 BETWEEN '2012-8-1' AND MonthEnd(2012,8,'1')

  • 2012-8-1 23:59:59.991+8 is within the time range specified by the next SQL statement:

    SELECT f2 FROM t52 WHERE f2 BETWEEN '2012-8-1' AND TIMESTAMP WITH TIME ZONE '2012-8-1 23.59.59.99999'

  Users will get correct results in most situations by entering (date) 23:59:59.99 (time zone) as month end values.

• Time zones

  Overseas PostERP users managing data of a target company must understand these:

  • All date time values refer to the time zone of the target company.

    Supposing you are entering data for company A which is in time zone UTC+8, then the following statements hold regardless of which time zone you are in:

    • Target company means company A. The begining of any month refers to company A's local time 00:00:00 and the end of any month refers to company A's local time 23:59:59.99. As such, all transactions recorded on or earlier than company A's local time 2012-5-31 23:59:59.99+8 are deemed as occurring in or before June, 2012.

    • The monthly ending date time values written by month end journal closing functions also refer to the target company's local time.

    • Users can choose to either include or exclude the time zones in the values when entering date time fields. For example, a Taiwan (UTC+8) user entering 2012-5-1 00:00:00+8 and 2012-5-1 00:00:00 gets the same result.

      Note however, this same user entering 2012-5-1 00:00:00+9 will in fact get 2012-4-30 23:15:00+0 saved to database.

    Specify companys' time zones on screen [M0F5].

  • users' time zones and the time lags between the target companys:

    PostERP display date time values according to indiviual users' time zones via thin client:

    • Assuming you are working in Taiwan using PostERP's thin client. If you pull out a closing record from company A, then the thin client might show you the closing date time as 2012-5-31 23:59:59.99+8.

    • Thin client will, however, show this same record to your England coleagues the date time as 2012-5-31 15:59:59.99+0.

• notes of date and time when designing dynamic report, data quick view, and business logic processor

  PostERP developers are recommended to refer to Section 17.4 this document for more information.