www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - Convert String to Date and Add =?UTF-8?B?wrFO?= Hours

reply Vahid <sabeti.ltd gmail.com> writes:
Hi,

I have a date string with the format of "2023-11-04 23:10:20". I 
want to convert this string to Date object and also, add ±N hours 
to it. For example:

`"2023-11-04 23:10:20" + "+2:00" = "2023-11-05 01:10:20"`
`"2023-11-04 23:10:20" + "-2:30" = "2023-11-05 20:40:20"`

How can I do this?
Nov 04 2023
next sibling parent reply Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:
On Saturday, November 4, 2023 12:11:53 PM MDT Vahid via Digitalmars-d-learn 
wrote:

 Hi,

 I have a date string with the format of "2023-11-04 23:10:20". I
 want to convert this string to Date object and also, add ±N hours
 to it. For example:

 `"2023-11-04 23:10:20" + "+2:00" = "2023-11-05 01:10:20"`
 `"2023-11-04 23:10:20" + "-2:30" = "2023-11-05 20:40:20"`

 How can I do this?


If you're using D's standard library, you would need to replace the space
with a T so that the time format was ISO extended. Then you can use
DateTime.fromISOEXtString() in std.datetim.date to get a DateTime. You can
then add a duration to the DateTime to change its value - e.g. using
hours(2) (or dur!"hours"(2) for the generic version). Then if you want
a string again, toISOExtString will convert the DateTime to the ISO extended
format, and if you want a space instead of a T, then just replace the T with
a space in the string. E.G.

import core.time : hours;
import std.array : replace;
import std.datetime.date : DateTime;

auto dt = DateTime.fromISOExtString(strBefore.replace(' ', 'T'));
dt += hours(2);
auto strAfter = dt.toISOExtString().replace('T', ' ');

However, if you also need to convert a string like "+2:00" to a Duration,
then you'll need to create a function like that yourself. If you already
have an integer value though, then you can just create a Duration and add it
to the DateTime.

At present D's standard library just supports the ISO standard, ISO extended
standard, and Boost's "simple" format for converting dates and times to and
from strings. And it doesn't support any format for converting from strings
to Durations. There are third party libraries on code.dlang.org which
support custom formatting for dates and times (e.g.
https://code.dlang.org/packages/ae), but I'm not familiar enough with any of
them to tell you how to solve your problem with them. That being said, since
you seem to haves strings that are almost in the ISO extendend format, it
should be pretty easy to get them to work with D's standard library.

- Jonathan M Davis
Nov 04 2023
parent Vahid <sabeti.ltd gmail.com> writes:
On Saturday, 4 November 2023 at 19:19:43 UTC, Jonathan M Davis 
wrote:

 On Saturday, November 4, 2023 12:11:53 PM MDT Vahid via 
 Digitalmars-d-learn wrote:

 [...]


 If you're using D's standard library, you would need to replace 
 the space
 with a T so that the time format was ISO extended. Then you can 
 use
 DateTime.fromISOEXtString() in std.datetim.date to get a 
 DateTime. You can
 then add a duration to the DateTime to change its value - e.g. 
 using
 hours(2) (or dur!"hours"(2) for the generic version). Then if 
 you want
 a string again, toISOExtString will convert the DateTime to the 
 ISO extended
 format, and if you want a space instead of a T, then just 
 replace the T with
 a space in the string. E.G.

 [...]


Thank you. It works very well.
Nov 06 2023
prev sibling parent reply Steven Schveighoffer <schveiguy gmail.com> writes:
On Saturday, 4 November 2023 at 18:11:53 UTC, Vahid wrote:

 Hi,

 I have a date string with the format of "2023-11-04 23:10:20". 
 I want to convert this string to Date object and also, add ±N 
 hours to it. For example:

 `"2023-11-04 23:10:20" + "+2:00" = "2023-11-05 01:10:20"`
 `"2023-11-04 23:10:20" + "-2:30" = "2023-11-05 20:40:20"`

 How can I do this?


Parse the date. There is a nice package on code.dlang.org that is 
for date parsing: https://code.dlang.org/packages/dateparser

-Steve
Nov 04 2023
parent Salih Dincer <salihdb hotmail.com> writes:
On Saturday, 4 November 2023 at 21:10:38 UTC, Steven 
Schveighoffer wrote:

 On Saturday, 4 November 2023 at 18:11:53 UTC, Vahid wrote:

 Hi,

 I have a date string with the format of "2023-11-04 23:10:20". 
 I want to convert this string to Date object and also, add ±N 
 hours to it. For example:

 `"2023-11-04 23:10:20" + "+2:00" = "2023-11-05 01:10:20"`
 `"2023-11-04 23:10:20" + "-2:30" = "2023-11-05 20:40:20"`

 How can I do this?


 Parse the date. There is a nice package on code.dlang.org that 
 is for date parsing: https://code.dlang.org/packages/dateparser

 -Steve


I couldn't get it to work, can you help me with this? I think the 
error is related to line 803 in the package.d file:


 import containers.dynamicarray : DynamicArray;


This means it is dependent on containers by Dlang Community.

This was installed it: 
https://github.com/dlang-community/containers

However I get these errors:


 dmd -w -of"bench.a" "bench.d" containers/package.d 
 dateparser/package.d

 /usr/bin/ld: bench.o:(.data.rel.ro+0x60): undefined reference 
 to `_D10containers12dynamicarray12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x78): undefined reference 
 to `_D10containers8internal4node12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x120): undefined reference 
 to `_D10containers12cyclicbuffer12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x128): undefined reference 
 to `_D10containers12dynamicarray12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x130): undefined reference 
 to `_D10containers7hashmap12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x138): undefined reference 
 to `_D10containers7hashset12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x140): undefined reference 
 to `_D10containers11openhashset12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x148): undefined reference 
 to `_D10containers5slist12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x150): undefined reference 
 to `_D10containers7treemap12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x158): undefined reference 
 to `_D10containers5ttree12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x160): undefined reference 
 to `_D10containers12unrolledlist12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x1c8): undefined reference 
 to `_D10dateparser9timelexer12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x1d0): undefined reference 
 to `_D10dateparser3ymd12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x1d8): undefined reference 
 to `_D10dateparser11parseresult12__ModuleInfoZ'
 /usr/bin/ld: bench.o:(.data.rel.ro+0x1e0): undefined reference 
 to `_D10dateparser10parserinfo12__ModuleInfoZ'
 /usr/bin/ld: bench.o: in function `_Dmain':


dateparser/package.d:(.text._Dmain[_Dmain]+0x1e): undefined 
reference to `_D10dateparser10parserinfo10ParserInfo7__ClassZ'

 /usr/bin/ld: dateparser/package.d:(.text._Dmain[_Dmain]+0x2f): 
 undefined reference to 
 `_D10dateparser10parserinfo10ParserInfo6__ctorMFNfbbZCQBzQBqQBh'
 /usr/bin/ld: bench.o: in function 
 `_D3std4conv__T6toImplTEQv8datetime4date5MonthTSQBt8typecons__T8NullableTiViN2147483648ZQzZQCyFQBwZQCy':


dateparser/package.d:

 .
 .
 .
 collect2: error: ld returned 1 exit status
 Error: linker exited with status 1


SDB 79
Nov 07 2023