Zig Datetime

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Table of Contents

• Usage

  • Outils

  • DateTime

  • Date

  • Timezone

  • Notes

  • Avancement

Usage

pub const Dte = @import("datetime").Date;  // work date Y M D

pub const Dtm = @import("datetime").DTime;  // UTC chronolog

pub const tmz = @import("timezones");       // Time zones


const allocator = std.heap.page_allocator;
const date = try Dte.create(2019, 12, 25);
const next_year = date.shiftDays(7);
assert(next_year.year == 2020);
assert(next_year.month == 1);
assert(next_year.day == 1);
const datuday= try. now(tmz.Europe.Paris);  // get milliTimestanp add timezones = YMD of day
  
// In UTC  milliTimestamp
const now = Dtm.now(tmz.Europe.Paris);
std.debug.print("formaChrono UTC : {s}\n",.{c.ChronoTime(allocator) catch "0" });
// formaChrono UTC : 2025-01-14T:11:25:37N:0491Z:000
std.debug.print("formaChrono NUM : {d}\n",.{c.ChronoNum(allocator) catch 0 });
// formaChrono NUM : 202501141125370491000

Notes

the time zone initialization process is performed once after each boot and only at the first function call. This is a principle used on the AS400 during OPDP (OPEN-DATA-SPACE).

This is a standard date processing library, plus a feature for SQL that supports a NULL zone.
See examples in the zig_sql project.

In SQL, there are two ways of handling dates:
“NULL”, e.g. invoicing not processed.

“0000-00-00” is not a valid date, it's just an indication, you shouldn't use it in your SQL.

The date becomes invalid, for example when a record is “deinit”.
Dte.DATE.dateOff(&dfacture), becomes “0000-00-00” its status changes to false.

Normally, if you don't fiddle with the date apart from retrieving twisted text,
there'll be no error, catch unreachable instead of tryv

To regenerate the timezone.zig file, run gensrc.sh from the create_timezones folder.
this file is generated from timedatectl

isBad The “isBad” function checks for consistent date completeness

If you use an uninitialized or already uninitialized field, or isBad this will trigger an @panic error. --> CRTL

To be dynamic, an LMDB file is generated at each reboot only if the readTimezone() function is used.

Time-zone processing in source file ./liboffset/timeoffset.zig

searchWeek” is a function that determines the number of weeks, the last week and the start of week 01.

Outils

Function	Description	Pub
checkLeapYear	is Leap Year	.
dayInYear	Number of days in the year	.
daysInMonth	Number of days in the month	.
daysBeforeYear	Number of days before Jan 1st of year	.
daysBeforeMonth	Number of days of the month precedent	.
isFile	openfileAbsolute lmdb	.

DateTime

Function	Description	Pub
HardTime	Change of field attribute	.
nowUTC	Timestamp date in UTC ONLY	x
nowTime	Timestamp date into Time-zone	x
Timestamp	Date time reverse timestamp	x
NumTime	Timestamp date into time-zone	x
stringTime	Date-time format string	x

Date

Function	Description	Pub	Panic	ctrl
create	Create and validate the date	x	?
dateOff	Change status OFF for work SQL = null	x
[isBad	Consistency test of the date	. [ *
copy	Return a copy of the date	x	x	x
HardDate	Change of field attribute	.
nowDate	Returns today's date into time-zone readTimezone()	x
eql	comparaison	x		x
comp	comparaison	x		x
gt	comparaison	x		x
gte	comparaison	x		x
lt	comparaison	x		x
lte	comparaison	x		x
parseIso	Parse date in format YYYY-MM-DD	x	x
parseFR	Parse date in format YYYY-MM-DD	x	x
parseUS	Parse date in format YYYY-MM-DD	x	x
string	Return date in ISO format YYYY-MM-DD	.		x
stringFR	Return date in ISO format DD-MM-YYYY	.		x
stringUS	Return date in ISO format MM-DD-YYYY	.		x
getYear	get year	x
getMonth	get Month	x
getDay	get Day	x
getWeek	get Week	x
getWeekDay	get WeekDay	x
restOfdays	get restOfdays	x
isWeekend	Test Week end	x
isLeapYear	is Leap Year	x
dayNum	number of days	.
daysMore	Add days	x		x
daysLess	Sub days	x		x
yearsMore	Add years	x		x
yearsLess	Sub years	x		x
quantieme	Returns the day number in the year	x		x
dayZeller	Calculation of day number with Sunday = 01...	.
searchWeek	Calculation week	.
fromOrdinal	Create a Date since 01-Jan-0001	.	x
toOrdinal	Return proleptic Gregorian ordinal	.

Timezone

Function	Description	Pub	Panic
abbrevDay	Return the abbreviation name of the day	x
nameDay	Return the of the day	x
abbrevMonth	Return the abbreviation name of the Month	x
abbrevDay	Return the abbreviation name of the day	x

Avancement

-2025-01-16 06:30 start projet date-time

-2025-01-16 15:01 add function switchMonths

-2025-01-30 04:47 Formatting @panic and modifying isBad() deleting assert()

-2025-02-25 20:08 Complete overhaul of the DATE model

-2025-02-25 20:08 Dynamic timezone set-up

-2025-02-25 20:08 Automatic creation of timezone.zig source code, via the module: Creat_timezones

-2025-02-25 20:08 LMDB database creation

-2025-02-25 20:08 module timeoffset

-2025-03-10 16:40 Resuming diagnostics with the better-understood 0.14.0 @src deciphering

-2025-03-14 16:10 module timeoffsetAdd arena-allocator , standardization with string and decimal

@panic