docker-jitsi-meet/base/rootfs/etc/cont-init.d/01-set-timezone

#!/usr/bin/with-contenv sh

if [ $TZ ]; then
    [ -f /usr/share/zoneinfo/$TZ ] && cp /usr/share/zoneinfo/$TZ /etc/localtime || echo "WARNING: $TZ is not a valid time zone."
    [ -f /usr/share/zoneinfo/$TZ ] && echo "$TZ" >  /etc/timezone
fi