1. I installed emacs 25.3_1 for Windows2. From cygwin shell, I did "/c/emacs25/emacs-25.3_1-x86_64/bin/emacs.exe -Q" 3. Within emacs, I did M-: (getenv "TZ") which returned "America/New York".4. Within emacs, I did M-: (current-time-string)5. The resulting time is using incorrect time zone.6. Inside cygwin, I did "export TZ=" to unset the TZ variable.7. Within emacs, I did M-: (getenv "TZ") which returned nil.8. Within emacs, I did M-: (current-time-string) to get correct time.My work around is to not set the TZ variable which is doable but not desirable.In GNU Emacs 25.3.1 (x86_64-w64-mingw32)of 2017-09-26 built on LAPHROAIGWindowing system distributor 'Microsoft Corp.', version 10.0.17134Configured using:'configure --without-dbus --without-compress-install 'CFLAGS=-O2-static -g3' PKG_CONFIG_PATH=/mingw64/lib/pkgconfig' Configured features:XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIBTOOLKIT_SCROLL_BARSImportant settings:value of $LANG: en_US.UTF-8locale-coding-system: cp1252Major mode: Lisp InteractionMinor modes in effect:tooltip-mode: tglobal-eldoc-mode: telectric-indent-mode: tmouse-wheel-mode: ttool-bar-mode: tmenu-bar-mode: tfile-name-shadow-mode: tglobal-font-lock-mode: tfont-lock-mode: tblink-cursor-mode: tauto-composition-mode: tauto-encryption-mode: tauto-compression-mode: tline-number-mode: ttransient-mark-mode: tRecent messages:For information about GNU Emacs and the GNU system, type C-h C-a."America/New_York"Quit"Mon May 14 15:28:21 2018"Load-path shadows:None found.Features:(shadow sort mail-extr emacsbug message dired format-spec rfc822 mmlmml-sec password-cache epg epg-config gnus-util mm-decode mm-bodiesmm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmailrfc2047 rfc2045 ietf-drums mm-util help-fns help-mode easymenucl-loaddefs pcase cl-lib mail-prsvr mail-utils time-date mule-utiltooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-typemwheel dos-w32 ls-lisp disp-table w32-win w32-vars term/common-wintool-bar dnd fontset image regexp-opt fringe tabulated-list newcommentelisp-mode lisp-mode prog-mode register page menu-bar rfn-eshadow timerselect scroll-bar mouse jit-lock font-lock syntax facemenu font-coreframe cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetanthai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanianslovak czech european ethiopic indian cyrillic chinese charscriptcase-table epa-hook jka-cmpr-hook help simple abbrev minibuffercl-preloaded nadvice loaddefs button faces cus-face macroexp filestext-properties overlay sha1 md5 base64 format env code-pages mulecustom widget hashtable-print-readable backquote w32notify w32 multi-ttymake-network-process emacs)Memory information:((conses 16 88765 5870)(symbols 56 19651 0)(miscs 48 44 85)(strings 32 15897 4470)(string-bytes 1 440523)(vectors 16 11730)(vector-slots 8 424140 5367)(floats 8 159 44)(intervals 56 236 56)(buffers 976 19))