(my-mins-between "11:30" "12:04")

(defun my-mins-between (time1 time2)
  "Return the minutes between HH:mm strings TIME1 and TIME2."
  (let ((diff (apply #'time-subtract
                     (mapcar (lambda (time)
                               (encode-time (decoded-time-set-defaults
                                             (parse-time-string time))))
                             (list time1 time2)))))
    (/ (float-time diff) 60)))

Debugger entered--Lisp error: (error "Invalid time specification")
  encode-time((0 30 11 1 1 0 nil -1 nil))
  (lambda (time) (encode-time (decoded-time-set-defaults (parse-time-string
time))))("11:30")
  mapcar((lambda (time) (encode-time (decoded-time-set-defaults
(parse-time-string time)))) ("11:30" "12:04"))


  In GNU Emacs 27.2 (build 1, x86_64-w64-mingw32)
 of 2021-03-26 built on CIRROCUMULUS
Repository revision: deef5efafb70f4b171265b896505b92b6eef24e6
Repository branch: HEAD
Windowing system distributor 'Microsoft Corp.', version 10.0.19041
System Description: Microsoft Windows 10 Home (v10.0.2004.19041.928)

Recent messages:
Quit
Mark set
Entering debugger...
Back to top level
my-mins-between
Entering debugger...
Back to top level
user-error: Beginning of history; no preceding item
user-error: End of history; no default available
scroll-up-command: End of buffer
command-execute: Command attempted to use minibuffer while in minibuffer
Configured using:
 'configure --without-dbus --host=x86_64-w64-mingw32
 --without-compress-install 'CFLAGS=-O2 -static''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY W32NOTIFY ACL GNUTLS LIBXML2
HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS MODULES THREADS JSON PDUMPER LCMS2 GMP

Important settings:
  value of $LANG: RUS
  locale-coding-system: cp1251

Major mode: Emacs-Lisp

Minor modes in effect:
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  company-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
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  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
c:/Users/pc/.emacs.d/elpa/flymake-1.1.1/flymake hides c:/Program
Files/Emacs/x86_64/share/emacs/27.2/lisp/progmodes/flymake
c:/Users/pc/.emacs.d/elpa/eldoc-1.11.0/eldoc hides c:/Program
Files/Emacs/x86_64/share/emacs/27.2/lisp/emacs-lisp/eldoc

Features:
(shadow sort mail-extr emacsbug sendmail help-fns radix-tree cl-print
debug backtrace bookmark pp gnutls network-stream url-http url-gw nsm
url-cache url-auth org-habitica vc-git diff-mode cl-extra help-mode
org-element avl-tree ol-eww eww mm-url url-queue ol-rmail ol-mhe ol-irc
ol-info ol-gnus nnir gnus-sum url url-proxy url-privacy url-expand
url-methods url-history mailcap shr url-cookie url-domsuf url-util svg
xml dom gnus-group gnus-undo gnus-start gnus-cloud nnimap nnmail
mail-source utf7 netrc nnoo parse-time iso8601 gnus-spec gnus-int
gnus-range message rmc puny rfc822 mml mml-sec epa derived epg
epg-config mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader gnus-win gnus nnheader gnus-util rmail
rmail-loaddefs rfc2047 rfc2045 ietf-drums text-property-search
mail-utils mm-util mail-prsvr wid-edit ol-docview doc-view jka-compr
image-mode exif dired dired-loaddefs ol-bibtex bibtex ol-bbdb ol-w3m
face-remap org-agenda org-refile org ob ob-tangle ob-ref ob-lob ob-table
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org-list org-faces org-entities time-date noutline outline easy-mmode
org-version ob-emacs-lisp ob-core ob-eval org-table org-keys
org-loaddefs find-func cal-menu calendar cal-loaddefs ol org-compat
advice org-macs format-spec company-oddmuse company-keywords
company-etags etags fileloop generator xref project company-gtags
company-dabbrev-code company-dabbrev company-files company-clang
company-capf company-cmake company-semantic company-template
company-bbdb company zerodark-theme let-alist pcase org-capture-complex
report 1cfresh process-1cbases process-docs flymake-proc flymake compile
comint ansi-color ring warnings thingatpt string-inflection
helm-easymenu edmacro kmacro rx info package easymenu browse-url
url-handlers url-parse auth-source cl-seq eieio eieio-core cl-macs
eieio-loaddefs password-cache json subr-x map url-vars seq byte-opt gv
bytecomp byte-compile cconv cl-loaddefs cl-lib tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp
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syntax facemenu font-core term/tty-colors frame minibuffer cl-generic
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korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote threads w32notify w32
lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 367719 37867)
 (symbols 48 24682 1)
 (strings 32 86256 2807)
 (string-bytes 1 3071501)
 (vectors 16 43765)
 (vector-slots 8 1238429 232140)
 (floats 8 271 108)
 (intervals 56 3530 533)
 (buffers 1000 33))