quek / simple-date-time

date and time library for common lisp

simple-date-time

date and time library for common lisp

simple-date-time's Issues

Time-zone in to-universal-time

Hello, I like & use simple-date-time library for its nice simplicity.
However, in the following code something wrong is occurring:

(- (encode-universal-time 0 0 0 1 1 2000 0)
   (simple-date-time:to-universal-time
    (simple-date-time:from-string "Sat, 01 Jan 2000 00:00:00 GMT")))
=> 32400

I think in function to-universal-time at date-time.lisp, encode-universal-time needs time-zone.
Because the default value of time-zone in encode-universal-time depends on system environment,
and 32400 = (* 9 60 60), 9 is JST offset.

c.f. http://clhs.lisp.se/Body/f_encode.htm , last example.

Use of month+ etc.

How should month+ etc be correctly used?

I wanted to do something like

(let* ((dt-right (from-posix-time ts))
       (dt-left  (month+ dt-right
                         (- +width-in-months+)))

but that doesn't work, as month+ modifies its argument!

That is unexpected, and as there's no copy operator, the only way to get this
is now something like

(let* ((dt-right (from-posix-time ts))
       (dt-left  (month+ (deserialize (serialize dt-right))
                         (- +width-in-months+)))

which looks really bad.

Shouldn't there be some functional interface, instead of modifying the passed
arguments?

Regards,

Phil

Addition of negative number of days leads to unexpected behaviour

I believe it's strange, but

(dt:day+ (dt:make-date 2020 10 2) -5)
returns
#<date-time 2020-09-30 00:00:00.000 00007fcd734e7030>
when I'd expected 2020-09-27.

Not sure how to get quicklisp package version. Tried on Fedora 32 x64 with SBCL-2.0.1, CLISP-2.49.93 and ECL-16.1.3

How does this compare to local-time?

https://common-lisp.net/project/local-time/manual.html

Which BSD license?

simple-date-time/simple-date-time.asd

Line 6 in d6992af

:license "BSD"

There is more than one "BSD" license. For example:

• BSD-2-Clause
• BSD-3-Clause
• BSD-4-Clause

Which BSD license does this project use?

Metadata for Quicklisp

Please consider adding :description, :author and :license information to your ASDF system. This will greatly help Quicklisp users and make it easier for them to report bugs.

More information:

http://blog.quicklisp.org/2015/05/looking-for-more-metadata.html
https://www.quicklisp.org

Clone date object?

Method day+ is destructive. So when I need original date and modified one I cant't see easy way to do it.