Custom and international time and date formats

Created by . Last modified on 2003/08/05.

Version 0.2

This howto explains how to create custom and international formats to insert time and date values in Zope. I gathered this information from the [email protected] mailing list. Feel free to get in touch about this document.

Version history

• 23rd October 1999 - version 0.1 - First draft
• 26th October 1999 - version 0.2 - Added references to the ZQRG

Simple timestamps

To enter the edit time for an objet, use:

<dtml-var bobobase_modification_time>

To enter the current time in Zope, use:

<dtml-var ZopeTime>

In both cases the result is a long timestamp in GMT format. Example:

1999/10/22 13:01:33.059 GMT+1

C-style format strings

If you want another format, you can use C-style format strings. Example:

<dtml-var bobobase_modification_time fmt="%d/%m/%Y - %H:%M">

You get the following results:

22/10/1999 - 11:01

Here is a table of useful C-style time and date formats. I copied it from a Linux reference document (I can't remember which one) for the C strftime function. Note that the output is GMT-based. So you cannot use these codes directly to format date and time values for say European timezones.

%a   An abbreviation for the day of the week. 
%A   The full name for the day of the week. 
%b   An abbreviation for the month name. 
%B   The full name of the month. 
%c   A string representing the complete date and time; on my 
     computer it's in the form: 10/22/99 19:03:23 
%d   The day of the month, formatted with two digits. 
%H   The hour (on a 24-hour clock), formatted with two digits. 
%I   The hour (on a 12-hour clock), formatted with two digits. 
%j   The count of days in the year, formatted with three digits 
     (from 001 to 366). 
%m   The month number, formatted with two digits. 
%M   The minute, formatted with two digits. 
%p   Either AM or PM as appropriate. 
%S   The second, formatted with two digits. 
%U   The week number, formatted with two digits (from 00 to 53; 
     week number 1 is taken as beginning with the first Sunday
     in a year). See also %W. 
%w   A single digit representing the day of the week: 
     Sunday is day 0.
%W   Another version of the week number: like %U, but 
     counting week 1 as beginning with the first Monday in a year. 
%x   A string representing the complete date; on my computer 
     it's in the format 10/22/99.
%X   A string representing the full time of day (hours, minutes, 
     and seconds), in a format like the following example: 13:13:13
%y   The last two digits of the year. 
%Y   The full year, formatted with four digits to include 
     the century. 
%Z   Defined by ANSI C as eliciting the time zone, if available; 
     it is not available in this implementation (which accepts %Z 
     but generates no output for it).
%%   A single character, %.

Note you can also use the following syntax:

<dtml-var "bobobase_modification_time().strftime('%d/%m/%Y - %H:%M')">

For more information about these formats, see the Zope Quick Reference Guide (section about the var tag).

The toZone method

The toZone('myTimeZone') method can be used to convert time/date values to a specific timezone. myTimeZone is a string that holds the name of the timezone. Example:

<dtml-var "bobobase_modification_time().toZone('US/Indiana-Starke')">

The output is:

1999/10/22 12:35:32.481 US/Indiana-Starke

The timezone names are defined in the Zope_dir\lib\python\DateTime\DateTimeZone.py file. I couldn't find one for most European timezones (Zope 2.0.1). Chris Allen has provided files to support Australian timezone names.

You can also add the C-formats mentioned above. Example:

<dtml-var "bobobase_modification_time(). toZone('US/Indiana-Starke').strftime('%d/%m/ %Y - %H:%M')">

Or

<dtml-var "bobobase_modification_time(). toZone('US/Indiana-Starke')" fmt="%d/%m/%Y - %H:%M">

Correcting a date or time value

You can add a value to a date to create a later date. You can also substract a value to create a sooner date. Example:

<dtml-var "ZopeTime() + 2">

The result date is 2 days from now, i.e. "1999/10/24 12:12:14.932 GMT+1" at the time of writing.

Metropolitan French time is GMT + 2 hours during summer time. 2 hours are 0.0833 day. So I guess I could use the following code to get a correct French date format:

<dtml-var "bobobase_modification_time() + 0.0833" fmt="%d/%m/%Y - %H:%M">

This works. However, it is quite ugly and it will break when we change to winter time. I'd need to store the correction value in a global variable.

Build-in functions

Martijn Pieters provided a better solution because AFAIK it doesn't need to be updated for winter time:

<dtml-with bobobase_modification_time>
  <dtml-var "'%s/%s/%i - %s' % (dd(), mm(), year(), 
  TimeMinutes())">
</dtml-with>

The output is:

22/10/1999 - 20:31

This is a Python expression. The 1st, 2nd and 4th functions return a string value. That's why we use the %s placeholder in the format. The 3rd function returns an integer. Hence the %i placeholder.

To customize this example for your own purpose you may need to modify or add placeholders. Example:

<dtml-with bobobase_modification_time>
  <dtml-var "'This is %s, %s/%s/%i, %s' % (Day(), mm(), dd(), 
  year(), TimeMinutes())">
</dtml-with>

The output is:

This is Friday, 10/22/1999, 20:44

For more information about the dd(), mm(), year(), TimeMinutes() and similar functions, see the Zope_dir\lib\python\DateTime\DateTime.html document in your Zope directory. See also the Zope Quick Reference Guide (DateTime section)

The complete expression is a bit complex. You could store it in a DTML method at the root of your Zope server and call it from documents in subdirectories. Example:

<dtml-var myDateTime>

The output is:

22/10/1999 - 20:50

I guess you could also write a small Python external method to easily store custom date formats. I haven't tried that yet. If you have code examples to offer feel free to send them over for inclusion in this document.