Cross-platform version of date -Iseconds in configure (#568)

* Cross-platform version of date -Iseconds

* date on MacOS 10.14 does not support %:z

* misreplaced string

* misreplaced string

configure

@@ -1313,8 +1313,8 @@ LIB_VER=`echo ${GRASS_VERSION_NUMBER} | sed 's/^\([0-9.]*\).*$/\1/'`
 GRASS_VERSION_GIT="exported"
 # get git short hash + date of last change in GRASS headers
 # (and anything else in include)
-GRASS_HEADERS_GIT_HASH=`date -u -Iseconds`
-GRASS_HEADERS_GIT_DATE=`date -u -Iseconds`
+GRASS_HEADERS_GIT_HASH=`date -u +%FT%T%z | sed 's/\(..\)$/:\1/'`
+GRASS_HEADERS_GIT_DATE=`date -u +%FT%T%z | sed 's/\(..\)$/:\1/'`
 # Extract the first word of "git", so it can be a program name with args.
 set dummy git; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
@@ -1355,11 +1355,11 @@ if test "$GIT" != "no" ; then
    fi
    GRASS_HEADERS_GIT_HASH=`$GIT log -1 --pretty=format:"%h" -- "${SRCDIR}/include" 2>/dev/null`
    if test -z "$GRASS_HEADERS_GIT_HASH"; then
-      GRASS_HEADERS_GIT_HASH=`date -u -Iseconds`
+      GRASS_HEADERS_GIT_HASH=`date -u +%FT%T%z | sed 's/\(..\)$/:\1/'`
    fi
-   GRASS_HEADERS_GIT_DATE=`date -d $($GIT log -1 --pretty=format:"%cI" -- "${SRCDIR}/include") -u -Iseconds` 2>/dev/null
+   GRASS_HEADERS_GIT_DATE=`date -d $($GIT log -1 --pretty=format:"%cI" -- "${SRCDIR}/include") -u +%FT%T%z | sed 's/\(..\)$/:\1/'` 2>/dev/null
    if test -z "$GRASS_HEADERS_GIT_DATE"; then
-      GRASS_HEADERS_GIT_DATE=`date -u -Iseconds`
+      GRASS_HEADERS_GIT_DATE=`date -u +%FT%T%z | sed 's/\(..\)$/:\1/'`
    fi
 fi
 

configure.in

@@ -142,8 +142,8 @@ changequote([,])
 GRASS_VERSION_GIT="exported"
 # get git short hash + date of last change in GRASS headers
 # (and anything else in include)
-GRASS_HEADERS_GIT_HASH=`date -u -Iseconds`
-GRASS_HEADERS_GIT_DATE=`date -u -Iseconds`
+GRASS_HEADERS_GIT_HASH=`date -u +%FT%T%z | sed 's/\(..\)$/:\1/'`
+GRASS_HEADERS_GIT_DATE=`date -u +%FT%T%z | sed 's/\(..\)$/:\1/'`
 AC_PATH_PROG(GIT, git, no)
 if test "$GIT" != "no" ; then
    GRASS_VERSION_GIT=`$GIT rev-parse --short HEAD 2>/dev/null`
@@ -152,11 +152,11 @@ if test "$GIT" != "no" ; then
    fi
    GRASS_HEADERS_GIT_HASH=`$GIT log -1 --pretty=format:"%h" -- "${SRCDIR}/include" 2>/dev/null`
    if test -z "$GRASS_HEADERS_GIT_HASH"; then
-      GRASS_HEADERS_GIT_HASH=`date -u -Iseconds`
+      GRASS_HEADERS_GIT_HASH=`date -u +%FT%T%z | sed 's/\(..\)$/:\1/'`
    fi
-   GRASS_HEADERS_GIT_DATE=`date -d $($GIT log -1 --pretty=format:"%cI" -- "${SRCDIR}/include") -u -Iseconds` 2>/dev/null
+   GRASS_HEADERS_GIT_DATE=`date -d $($GIT log -1 --pretty=format:"%cI" -- "${SRCDIR}/include") -u +%FT%T%z | sed 's/\(..\)$/:\1/'` 2>/dev/null
    if test -z "$GRASS_HEADERS_GIT_DATE"; then
-      GRASS_HEADERS_GIT_DATE=`date -u -Iseconds`
+      GRASS_HEADERS_GIT_DATE=`date -u +%FT%T%z | sed 's/\(..\)$/:\1/'`
    fi
 fi