Re: Les fuseaux horaires ambiguës ou même manquant.

D'ailleurs, si cela peux intéresser quelqu'un, voici la petite fonction Bash que j'utilisai pour convertir une date dans les fuseaux horaires utiles pour mon boulot.

# tz <TIME SPECIFICATION> 
#
# Display the specified time in multiple timezones (default is "now").
#
# Timezones are sorted by their UTC offsets.
#
# Timezones with the same UTC offset than the current timezone
# are marked with '*'
#
# However, they are marked with '?' instead if the current time
# and the specified time are not equal which usually indicates
# a summer/winter time change. 
#
# Examples: (see 'info date' for more)
#
# tz : for current time (or "now") 
# tz 14:00 : for 14:00 today in the current timezone
# tz 14:00+4 : for 14:00 today in UTC+4 
# tz tomorrow 2pm PST : for 14:00 tomorrow in Pacific Standard Time 
# tz 2pm July 3 CEST : for Friday July 3 14:00 2015 in Central European Summer Time 
#
# Remark: Not all symbolic timezone names work as expected.
# First because some of them are only valid during parts of the year (e.g CET
# vs CEST in Central Europe) and also because some names are ambiguous
# (e.g. CST may refer to Central Standard Time in the US and to China Standard Time
# in Chine). Using UTC or GMT relative timezones is usually safer.
#
# http://www.timeanddate.com/time/map/
#
tz () {
 local FMT A D T tz M UTC0 UTC1 LOCATIONS 
 D="$*"
 # Output format (see man 1 date)
 FMT="%H:%M %_4Z (UTC%:z) %a %b %d"
 # FMT="%c %Z (UTC%:z)"
 [ -n "$D" ] || D=now 
 T=$(date -d "$D" +%s) || return
 # Add here your preferred locations (as given by tzselect)
 LOCATIONS+=" America/Los_Angeles" # PST/PDT
 #LOCATIONS+=" America/Denver" # MST/MDT
 LOCATIONS+=" America/Chicago" # CST/CDT
 LOCATIONS+=" America/New_York" # EST/EDT
 LOCATIONS+=" Europe/London" # GMT/BST
 LOCATIONS+=" Europe/Paris" # CET/CEST 
 #LOCATIONS+=" Asia/Shanghai" # CST (China Standard Time)
 LOCATIONS+=" Asia/Tokyo" # JST 
 #LOCATIONS+=" Australia/Melbourne" # AEDT/AEST
 #LOCATIONS+=" Australia/Adelaide" # ACDT/ACST
 # Get current timezone now (in $UTC0) and at requested time (in $UTC1)
 # They may be different because of summer/winter time changes. 
 UTC0=$(LC_ALL=C date -d "now" +"%z")
 UTC1=$(LC_ALL=C date -d "@$T" +"%z")
 for tz in $LOCATIONS ; do
 # UTC2 is the UTC timezone of $tz at the given time 
 UTC2=$(LC_ALL=C TZ="$tz" date -d "@$T" +"%z")
 if [ "$UTC1" == "$UTC2" ] ; then
 if [ "$UTC0" == "$UTC1" ] ; then
 M="*" # This is consistent with current timezone.
 else
 M="?" # Also but probably with a summer/winter time change.
 fi
 else
 M=" "
 fi
 A=$(LC_ALL=C TZ="$tz" date -d "@$T" +"$FMT")
 # Prefix each output line with its numeric timezone. 
 # That prefix will we removed after sorting.
 printf "%s %c%-20s %s\n" "$UTC2" "$M" "$tz" "$A"
 done | sort -n | cut -c 7-
}