Date & Time operations

Server side date validation 

if { [catch { set end_date_ansi [clock format [clock scan 2011-10-33] -format %Y-%m-%d] } ""] } {
   ad_return_complaint 1 "Wrong date"
}­

 $ tclsh8.5
 % clock format [clock scan "January 1, 2040"]
 Sun Jan 01 00:00:00 EST 2040

 $ tclsh8.4
 % clock format [clock scan "January 1, 2040"]
 unable to convert date-time string "January 1, 2040"
 % clock format [clock scan "Dec 31, 2038"]
 unable to convert date-time string "Dec 31, 2038"
 %

Server side date validation using regular expressions

Validate a date (form­at: dd.mm.yyyy)­

proc isdate {str} {
    if {![regexp {^(?:(?:[0-2]\d|30)\.(?:1\d|0[^2])|31\.(?:0[13578]|1[02])|([0-1]\d|2\d)\.02)\.(\d{4})$} $str "" t y] || ($t == 29 && ($y % 4 || ($y % 100 == 0 && $y % 400)))} { return 0 }
    return 1
}

^(?:(?:31(\/|-|\.)(?:0?[13578]|1[02]))\1|(?:(?:29|30)(\/|-|\.)(?:0?[1,3-9]|1[0-2])\2))(?:(?:1[6-9]|[2-9]\d)?\d{2})$|^(?:29(\/|-|\.)0?2\3(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))$|^(?:0?[1-9]|1\d|2[0-8])(\/|-|\.)(?:(?:0?[1-9])|(?:1[0-2]))\4(?:(?:1[6-9]|[2-9]\d)?\d{2})$

Server side date validation using ad_form­

• http://openacs.org/forums/message-view?message_id=91182
• http://openacs.org/forums/message-view?message_id=45717

Server side date validation using template::util::date

template::util::date::validate "2020-12-31" err_ref
0
template::util::date::validate "2020-13-31" err_ref
0

Server side date validation using tcl - Other helpful links:

• http://groups.google.com/group/comp.lang.tcl/browse_thread/thread/e0606689063aa3cc

Type conversations & Formatting

Ansi to Julian­

set start_date_julian [dt_ansi_to_julian_single_arg $date_ansi]

Julian to Ansi

set current_date_ansi [dt_julian_to_ansi $julian_date]

Formatting

clock format [clock scan "20120128"] -format {%Y-%m-%d}

Formatting in sql query

Calculation

set end_date_ansi [db_string get_previous_month "SELECT '$start_date_ansi'::date+'1 month'::interval-'1 day'::interval" -default 0]
clock format [clock scan {+7 days} -base [clock scan {2012-04-05}] ] -format %Y-%m-%d

Other

Date today

[clock format [clock seconds] -format {%Y-%m-%d}]

Number of days of a month

set number_days_month [db_string get_number_days_month "SELECT date_part('day','$first_day_of_month'::date + '1 month'::interval - '1 day'::interval)" -default 0]

Last day of a month:

set last_day_of_month [db_string get_number_days_month "select to_date( '$cap_year' || '-' || '$cap_month' || '-' || '$number_days_month','yyyy-mm-dd')+1 from dual;" -default 0]

Get current day month:

set current_date_ansi [db_string julian_date_select "select to_char( to_date(:julian_date,'J'), 'YYYY-MM-DD') from dual"]

Localize Date (user locale):

set form_start_date [lc_time_fmt [parameter::get_from_package_key -package_key "intranet-cost" -parameter DefaultStartDate -default "2010-01-01"] "%x" locale]

Other:

set end_date_ansi [append "" [string range $current_date_ansi 0 7] $number_days_month]