tieske / date Goto Github PK

Consider code below:

local d = date(2011, 1, 1):setisoweeknumber(20, 1)
print(d)

For some reason the resulting year is 2010, not 2011 as expected! It's easy to work around this simply by doing :setisoyear(2011, 20, 1). Maybe you need to do something similar at the method?

Hi.

First day of week can be sunday or monday. Are possible define it on library (or object)?
Maybe interesting have a minimal support to day of week and months.

...
local now = date(false, 'pt-br' or { table with values });
print( now:fmt(%A") ) -> "Terça-feira" instead "Tuesday"
...

$ lua-5.1 -v
Lua 5.1.5 Copyright (C) 1994-2012 Lua.org, PUC-Rio

$ lua-5.1 test.lua
20170101 2017-01-01T00:00:00
20170201 2017-02-01T00:00:00
20173131 2019-07-31T00:00:00

$ cat test.lua
date = require 'date'

t = {
'20170101',
'20170201',
'20173131' --- proposital 'invalid' date
}

for i=1, #t do
x = t[i];
print( x, date(x):fmt('${iso}') );
end

According to the documentation https://tieske.github.io/date/
Section 7.2. Supported MetaMethods
The a < b operation.
Returns true if date value of a is later than date value of b. a > b is equivalent to b < a.

Luckily it is implemented the intuitive way, but the documentation seems to be incorrect.

local A = date(2021, 7, 1)
local B = date(2021, 7, 2)
print(A < B)

prints true which is correct.

and now while writing this issue I might understand what is going on

the issue is the word "later" in the description. For me "later" means "after", a day in the future, like in the sentence "at a later point in time".
I think the word used should be "older".

The a < b operation.
Returns true if date value of a is older than date value of b. a > b is equivalent to b < a.

Would you agree?

Thank you

marco

I think there is an ambiguity in the standard library that makes it impossible to handle user-supplied dates with time zones.

The docs don't say whether date("some date") parses to a date that is always in UTC or whether it parses to a date that is always local. Sometimes the date function appears to return UTC dates when given a time zone:

th> date("2016-01-05T23:14:33Z")
Tue Jan 05 2016 23:14:33.000000000

th> date("2016-01-05T18:14:33-5")
Tue Jan 05 2016 23:14:33.000000000

th> date("2016-01-05T18:14:33 EST")
Tue Jan 05 2016 23:14:33.000000000

But sometimes, the output of date() is clearly local:

th> date()
Tue Jan 05 2016 12:51:42.000000000

th> date("2016-01-05 12:51")
Tue Jan 05 2016 12:51:00.000000000

Perhaps I can make my code always use UTC dates by calling :toutc() on the output of date() . I thought this would make the issue go away: if the user supplied a local date, then it would be converted to UTC. Unfortunately, this doesn't work. This library doesn't store the actual time zone in the date object, so calling :toutc() mutates dates that were already UTC:

th> date()
Tue Jan 05 2016 12:38:27.000000000

th> date():toutc()
Tue Jan 05 2016 17:38:29.000000000

th> date():toutc():toutc()
Tue Jan 05 2016 22:38:31.000000000

th> date():toutc():toutc():toutc()
Wed Jan 06 2016 03:38:32.000000000

This creates a problem. If I'm trying to parse a user-supplied date, I can't tell whether they specified a time zone or not. This means I can't know whether I need to call :toutc() on the result. And because :toutc() changes the time value, getting this wrong will cause me to incorrectly handle that date. Oy.

What should I do here?

I could not get this to work under Lua 5.2
I changed the references to 'arg' (which no longer seems to exist) to select(n,..)
eg
function date:__call(...)
local n = select("#",...)
if n > 1 then return (date_from(...))
elseif n == 0 then return (date_getdobj(false))
else local o, r = date_getdobj(select(1,...)); return r and o:copy() or o end
end

Hi. I tried to install luadate in my torch framework (luajit)

require 'date'

/opt/torch/share/lua/5.1/luarocks/loader.lua:113: error loading module 'date' from file '/opt/torch/share/lua/5.1/date.lua':
/opt/torch/share/lua/5.1/date.lua:338: invalid escape sequence near '"^(%d+)[/'
stack traceback:
[C]: in function 'loader'
/opt/torch/share/lua/5.1/luarocks/loader.lua:113: in function </opt/torch/share/lua/5.1/luarocks/loader.lua:110>
[C]: in function 'f'
[string "local f = function() return require 'date' en..."]:1: in main chunk
[C]: in function 'xpcall'
/opt/torch/share/lua/5.1/trepl/init.lua:553: in function </opt/torch/share/lua/5.1/trepl/init.lua:489>

http://rocks.moonscript.org is now the main module host for Lua modules. The current date module isn't owned by anyone. If you have an account on moonrocks I can move ownership to you so it's easy to upload new versions.

https://rocks.moonscript.org/modules/luarocks/date

Integer seconds, offset is parsed:

> pcall(p, '2023-08-22T24:40:23-02:00')
true    Wed Aug 23 2023 02:40:23.000000000

Decimal seconds, offset is not parsed:

> pcall(p, '2023-08-22T24:40:23.0-02:00')
true    Wed Aug 23 2023 00:40:23.000000000

Hi Tieske,

We are looking for a library at Lua, which can parse duration at ISO8601.
For example, PT10S is 10 seconds. Is it luadate possible to parse duration? Thanks.

--- source
local date = dofile('date.lua')

x = '2018-31-02';
print( date(x):fmt('${iso}') );

--- output ---
$ lua-5.1 test.date.lua
2020-07-02T00:00:00

when create a date by date(true), set the utc field to be true.

when create a local date, set the utc field to be false.

tolocal method check this field first, if utc field is false, tolocal does nothing and return self, if utc field is true, tolocal convert the date and time value to local time, and then set the utc field of return value to be false.

toutc method check this field first, too. if utc field is true, toutc does nothing and return self, if utc field is false, toutc convert the date and time value to utc time, and then set the utc field of return value to be true.

...

code contains usage of deprecated arg.n methods.

Hi.

0. lua-5.4.4 (vanilla) / gcc version 11.2.0 / cygwin 64-bit

1. When compile lua-5.4.4 with CFLAGS: -std=c99 -DLUA_COMPAT_APIINTCASTS=1 -DLUA_32BITS=1

$ ./lua -e "date=require 'date'; io.write( _VERSION, '\n', os.date(), '\n', date():fmt('%Y-%m-%dT%T'), '\n\n');"
Lua 5.4
Thu Mar 24 14:26:51 2022
2009-09-10T00:07:51

2. When compile lua-5.4.4 with CFLAGS: -std=c99 -DLUA_COMPAT_APIINTCASTS=1

$ ./lua -e "date=require 'date'; io.write( _VERSION, '\n', os.date(), '\n', date():fmt('%Y-%m-%dT%T'), '\n\n');"
Lua 5.4
Thu Mar 24 14:31:12 2022
2022-03-24T14:31:12

At https://github.com/Tieske/date/blob/master/src/date.lua#L346
The setz is sending 2 parameters and only can receive one.

How do I get the timestamp from a date object?

Hi,

First of all, congratulations for this excellent module which greatly simplifies the use of dates in Lua.

I'm writing a timestamp -> iso8601 converter using this module and I'm having a problem when the clock switches from summer time to winter time.
I am in France and on October 29, 2023 we switch to winter time.

I wrote this little piece of code:

local date = require('date')

local ts1 = 1698537600 -- 2023-10-29T00:00:00Z or 2023-10-29T02:00:00+02:00
local ts2 = 1698541200 -- 2023-10-29T01:00:00Z or 2023-10-29T02:00:00+01:00
local d1, d2 = date(ts1), date(ts2)
local d1, d2 = date(ts1), date(ts2)
print("ts1 iso8601 UTC  :", d1:fmt("${iso}Z"))
print("ts2 iso8601 UTC  :", d2:fmt("${iso}Z"))
local d1local, d2local = date(ts1):tolocal(), date(ts2):tolocal()
print("ts1 iso8601 local:", d1local:fmt("${iso}") .. d1local:fmt("%z"))
print("ts2 iso8601 local:", d2local:fmt("${iso}") .. d2local:fmt("%z"))

And I get the following display::

ts1 iso8601 UTC  :	2023-10-29T00:00:00Z --> good
ts2 iso8601 UTC  :	2023-10-29T01:00:00Z --> good
ts1 iso8601 local:	2023-10-29T02:00:00+0100 --> bad
ts2 iso8601 local:	2023-10-29T02:00:00+0100 --> good

Is there a problem in the module or is it a problem using the module on my side?

Hey,

I was doing some research, but I still can't find out, how could I print the local hours in Miami, FL. GMT-4000
Because unfortunately, the server where I am running on located in Central Europe, in this case, I would just somehow set the hours to -6 I guess (local time is Budapest).

But I have no clue how to do that. Right now it just gets the current time. Also for some strange reason, the seconds ends without zero, so if the current seconds are 8 for example, it returns 20:25:8 instead of 20:25:08, but if that cant' be solved, I can live with that.

a = date()
h, m, s = a:gettime()
print(h.. ":"..m..":"..s)

Could you put me to the right way to get the correct timezone?

Hi! this library support SQL-like date/time/timestamp types?

Thanks!

l.lua

date = require "date"
macros = {}

function macros.dateFunc(dataObj, format)
    local finds = { 'a', 'A', '[^%%]d', 'D', 'F', 'g', 'G', 'h', 'i', 'j', 'l', '[^%%]m', '[^%%]M', 'n', 'N', 'o', '[^%%]s', '[^%%]w', '[^%%]W', '[^%%]y', '[^%%]Y' }
    local replaces = { '%%p', '%%p', '%%d', '%%a', '%%B', '%%I', '%%H', '%%I', '%%M', '%%d', '%%A', '%%m', '%%b', '%%m', '%%u', '%%G', '%%S', '%%w', '%%W', '%%y', '%%Y' }
    for i = 1, #finds, 1 do
        format = string.gsub(format, finds[i], replaces[i])
    end
    return date(dataObj):fmt(format)
end

return macros

test/l.test.lua

package.path = package.path .. ';../l.lua';

transfer = require('l.lua')
luaunit = require('luaunit')


TestDate = {}
function TestDate:testString()
    local format = 'a  A  d  D  F  g  G  h  i  j  l  m  M  n  N  o  s  w  W  y  Y'
    local expected = 'PM  PM 19  Wed  July  12  12  12  30  19  Wednesday 07 Jul  07  3  2017 15 3 29 17 2017'
    luaunit.assertEquals(transfer.dateFunc("2017-7-19 12:30:15", format), expected)
end

-- end of table TestDate

os.exit(luaunit.LuaUnit.run())

I run lua ltest.lua Error:

lua: error loading module 'date' from file '../l.lua':
	../l.lua:8: too many C levels (limit is 200) in function at line 4 near 'i'
stack traceback:
	[C]: in ?
	[C]: in function 'require'
	../l.lua:1: in main chunk
	[C]: in function 'require'
	../l.lua:1: in main chunk
	[C]: in function 'require'
	../l.lua:1: in main chunk
	[C]: in function 'require'
	../l.lua:1: in main chunk
	[C]: in function 'require'
	...
	[C]: in function 'require'
	../l.lua:1: in main chunk
	[C]: in function 'require'
	../l.lua:1: in main chunk
	[C]: in function 'require'
	../l.lua:1: in main chunk
	[C]: in function 'require'
	../l.lua:1: in main chunk
	[C]: in function 'require'
	ltest.lua:3: in main chunk
	[C]: in ?