Run "TZ=UTC0 admin/update-copyright".

* lisp/calc/calc-aent.el (calc-do-quick-calc)
(calc-do-calc-eval, math-build-parse-table):
* lisp/calc/calc-alg.el (math-polynomial-base):
* lisp/calc/calc-alg.el (math-is-poly-rec):
* lisp/calc/calc-arith.el (calcFunc-scf):
* lisp/calc/calc-arith.el (math-ceiling, math-round):
* lisp/calc/calc-arith.el (math-trunc-fancy, math-floor-fancy):
* lisp/calc/calc-ext.el (calc-init-extensions, calc-reset)
(calc-refresh-top, calc-z-prefix-help, calc-binary-op-fancy)
(calc-unary-op-fancy):
* lisp/calc/calc-forms.el (math-make-mod):
* lisp/calc/calc-frac.el (calcFunc-frac):
* lisp/calc/calc-funcs.el (calcFunc-euler):
* lisp/calc/calc-help.el (calc-full-help):
* lisp/calc/calc-lang.el (c, pascal, fortran, tex, latex, eqn)
(yacas, maxima, giac, math, maple):
* lisp/calc/calc-macs.el (calc-wrapper, calc-slow-wrapper):
* lisp/calc/calc-map.el (calc-get-operator, calcFunc-mapeqr)
(calcFunc-reducea, calcFunc-rreducea, calcFunc-reduced)
(calcFunc-rreduced, calcFunc-outer):
* lisp/calc/calc-misc.el (another-calc, calc-do-handle-whys):
* lisp/calc/calc-mode.el (calc-save-modes):
* lisp/calc/calc-mtx.el (math-col-matrix, math-mul-mat-vec):
* lisp/calc/calc-poly.el (math-sort-terms, math-poly-div-list)
(math-mul-list, math-sort-poly-base-list)
(math-partial-fractions):
* lisp/calc/calc-prog.el (calc-user-define-formula):
* lisp/calc/calc-rewr.el (math-rewrite, math-compile-patterns)
(math-compile-rewrites, math-parse-schedule)
(math-rwcomp-pattern):
* lisp/calc/calc-store.el (calc-var-name-map, calc-let)
(calc-permanent-variable, calc-insert-variables):
* lisp/calc/calc-stuff.el (calc-flush-caches, calcFunc-pclean)
(calcFunc-pfrac):
* lisp/calc/calc-units.el (math-build-units-table)
(math-decompose-units):
* lisp/calc/calc-vec.el (calcFunc-mrow, math-mat-col)
(calcFunc-mcol, math-mat-less-col, math-mimic-ident):
* lisp/calc/calc-yank.el (calc-edit):
* lisp/calc/calc.el
(calc-mode-var-list-restore-default-values)
(calc-mode-var-list-restore-saved-values, calc-mode, calc-quit):
* lisp/calc/calccomp.el (math-compose-expr)
(math-compose-matrix, math-vector-to-string): Don't quote lambdas with
'function'.

Includes the following pervasive changes:
- Move some defvars earlier in the file so they cover earlier let-bindings
- Change dynamically scoped `calc-FOO` or `math-FOO` function arguments
  to just FOO and then let-bind the `calc-FOO` or `math-FOO` variable
  explicitly in the body of the function.  In some cases, the
  beginning of the function was changed to refer to FOO so as to delay
  the binding to a nearby `let` when I could ensure that it did
  not make a difference.
- Add an underscore in front of unused vars or comment them out altogether.
- Replace unused `err` arg to `condition-case` with nil.

Plus the additional itemized changes below.

* lisp/calc/calc-map.el (calcFunc-reducer):
* lisp/calc/calc-arith.el (math-setup-declarations):
* lisp/calc/calc-help.el (calc-full-help, calc-help-index-entries)
(calc-full-help): Use `ignore-errors`.

* lisp/calc/calc-embed.el (calc-embedded-modes-change):
Declare `the-language` and `the-display-just` as dynamically scoped.

* lisp/calc/calc-forms.el (math-setup-year-holidays): Use `dolist`.

* lisp/calc/calc-graph.el (calc-graph-set-styles): Use `symbol-value`
rather than `eval.`
(calc-graph-delete-temps, calc-graph-set-styles): Use ignore-errors.

* lisp/calc/calc-macs.el (calc-with-trail-buffer): Add artificial use
of `save-buf` to silence compiler warnings in all the cases where
`body` doesn't make use of it.

* lisp/calc/calc-math.el (math-largest-emacs-expt)
(math-smallest-emacs-expt, math-use-emacs-fn): Use ignore-errors.

* lisp/calc/calc-mode.el (calc-total-algebraic-mode): Remove "P" from
interactive spec since it's not used anyway.

* lisp/calc/calc-rewr.el (calc-match): Simplify.

* lisp/calc/calc.el (calc-buffer): Give it a global nil value,
so it's automatically declared dynbound in any file that requires `calc`.
(calcDigit-nondigit): Adjust accordingly.

* lisp/calc/calcalg2.el (calcFunc-table): Declare `var-dummy` as dynbound.
(math-scan-for-limits): Comment out dead code.

* lisp/calc/calcalg3.el (math-general-fit): Declare `var-YVAL` and
`var-YVALX` as dynbound.

The number of days from epoch to Jan 1, 1970 that was used in parsing
and formatting Unix time was incorrect.  The previous fix
(in e368697ce36) was incomplete.

Reported by Vincent Belaïche.

* lisp/calc/calc-forms.el (math-unix-epoch): New constant.
(math-format-date-part, math-parse-standard-date, calcFunc-unixtime):
Use math-unix-epoch instead of a constant that is sometimes wrong.
* test/lisp/calc/calc-tests.el (calc-unix-date): New test.

The calculation of business days was broken in 2012 (probably
310e60d9454fe2 or thereabouts) when the date representation changed
epoch so that Jan 1, 1 AD became day number 1 instead of 0.  Repair
this, along with an unrelated bug that prevented arbitrary holiday
weekdays from working.

Reported by Aaron Zeng.

* lisp/calc/calc-forms.el (math-to-business-day)
(math-from-business-day): Correct calculation of weekdays using Calc's
current (Rata Die) chronology.  Modify loop condition to cope with odd
sets of holiday weekdays.
* test/lisp/calc/calc-tests.el (calc-business-days): New test.

Run "TZ=UTC0 admin/update-copyright $(git ls-files)".

* doc/emacs/calendar.texi (Calendar Systems)
* doc/lispref/os.texi (Time Conversion):
Prefer "BC" to "B.C." since the documentation generally uses "BC".
* doc/misc/emacs-mime.texi (time-date):
* lisp/calendar/time-date.el (date-to-day, time-to-days):
In the doc string, state the day origin more clearly, and more
consistently with the rest of the documentation.
* src/timefns.c (Fdecode_time): State the year origin in
the doc string.

* lisp/apropos.el (apropos-do-all):
* lisp/auth-source-pass.el (auth-source-pass--select-from-entries):
* lisp/auth-source.el (auth-source-user-or-password):
* lisp/calc/calc-forms.el (math-tzone-names):
* lisp/calendar/diary-lib.el (diary-face-attrs)
(diary-mark-entries-1):
* lisp/cedet/cedet-files.el (cedet-files-list-recursively):
* lisp/cedet/ede.el (ede-constructing, ede-deep-rescan):
* lisp/cedet/ede/cpp-root.el (ede-cpp-root-header-file-p):
* lisp/cedet/ede/proj.el (ede-proj-target-makefile):
* lisp/cedet/inversion.el (inversion-check-version)
(inversion-test):
* lisp/cedet/mode-local.el (mode-local-map-file-buffers):
* lisp/cedet/semantic/complete.el (semantic-displayer-ghost):
* lisp/cedet/semantic/db-find.el (semanticdb-find-translate-path-default):
* lisp/cedet/semantic/db.el (semanticdb-table)
(semanticdb-search-system-databases):
* lisp/cedet/semantic/imenu.el (semantic-imenu-index-directory):
* lisp/cedet/semantic/java.el (semantic-java-doc-keywords-map):
* lisp/cedet/semantic/lex-spp.el (semantic-lex-spp-use-headers-flag):
* lisp/cedet/semantic/lex.el (semantic-lex-make-keyword-table)
(semantic-lex-make-type-table, semantic-lex-debug-analyzers):
* lisp/cedet/semantic/tag-ls.el (semantic-tag-abstract-p)
(semantic-tag-leaf-p, semantic-tag-static-p)
(semantic-tag-prototype-p):
* lisp/dnd.el (dnd-open-remote-file-function, dnd-open-local-file):
* lisp/emacs-lisp/eieio-opt.el (eieio-build-class-alist)
(eieio-read-class, eieio-read-subclass):
* lisp/emacs-lisp/generator.el (cps--replace-variable-references)
(cps--handle-loop-for):
* lisp/erc/erc-dcc.el (erc-dcc-list, erc-dcc-member, erc-dcc-server)
(erc-dcc-auto-mask-p, erc-dcc-get-file, erc-dcc-chat-accept):
* lisp/eshell/em-pred.el (eshell-pred-file-type):
* lisp/faces.el (defined-colors-with-face-attributes):
* lisp/font-core.el (font-lock-mode):
* lisp/frame.el (frame-restack):
* lisp/net/shr.el (shr-image-animate):
* lisp/org/org-agenda.el (org-agenda-change-all-lines)
(org-agenda-today-p):
* lisp/org/org-id.el (org-id-get):
* lisp/org/org.el (org-highlight-latex-and-related)
(org--valid-property-p):
* lisp/org/ox-beamer.el (org-beamer--get-label):
* lisp/org/ox-latex.el (org-latex--caption-above-p):
* lisp/org/ox-odt.el (org-odt--copy-image-file)
(org-odt--copy-formula-file):
* lisp/org/ox.el (org-export-with-timestamps):
* lisp/progmodes/verilog-mode.el (verilog-indent-declaration-macros):
* lisp/ses.el (ses-file-format-extend-parameter-list):
* lisp/term.el (ansi-term):
* lisp/textmodes/bibtex.el (bibtex-no-opt-remove-re)
(bibtex-beginning-of-first-entry, bibtex-autokey-get-title)
(bibtex-read-key, bibtex-initialize):
* lisp/textmodes/flyspell.el (flyspell-word):
* lisp/view.el (view-mode-exit):
* src/composite.c:
* src/floatfns.c (Fisnan): Fix typos in docstrings.

This adds FIXMEs to areas where Lisp code should support
subsecond information in broken-down timestamps.
It also fixes some unnecessary truncation of timestamps, and
ports the code to a hypothetical future Emacs version where
(decode-time) returns subsecond timestamps by default.
* lisp/calc/calc-forms.el (calc-time, math-iso-dt-to-date)
(calcFunc-now):
* lisp/calendar/icalendar.el (icalendar--add-decoded-times):
* lisp/calendar/iso8601.el (iso8601-parse-interval):
Truncate seconds to an integer, and add a FIXME about
subseconds support.
* lisp/calendar/icalendar.el (icalendar--decode-isodatetime)
(icalendar--decode-isoduration):
Add a FIXME about subseconds support.
* lisp/gnus/gnus-delay.el (gnus-delay-article):
Don’t truncate seconds to an integer, as there’s no need
to do that here.
* lisp/gnus/gnus-util.el (gnus-seconds-today)
(gnus-seconds-month, gnus-seconds-year):
* lisp/gnus/message.el (message-make-expires-date):
* lisp/org/org-timer.el (org-timer-show-remaining-time):
* lisp/vc/ediff-mult.el (ediff-format-date):
Truncate seconds to an integer, as that’s what’s wanted here.
* lisp/midnight.el (midnight-next):
Ceiling seconds to an integer, as that’s what wanted here.

* lisp/calc/calc-forms.el (math-absolute-from-gregorian-dt):
Rewrite in a way that I understand, and that actually seems to work.
(math-absolute-from-julian-dt): Use Julian, not Gregorian, leap year
rules for counting days within a year.
(math-julian-date-beginning, math-julian-date-beginning-int):
Change constants to be consistent with their doc strings and the code:
use Rata Die epoch at Dec 31, 1 BC Gregorian proleptic, not Julian.
* doc/misc/calc.texi (Date Forms): Correct difference between Julian
Day and Rata Die.
* test/lisp/calc/calc-tests.el (calc-test-calendar): New test.