All of them are commented apart the europe, as you can see:
# NTP Server
# NTP_SERVER=time.gpsonextra.net
# Asia
# NTP_SERVER=asia.pool.ntp.org
# Europe
NTP_SERVER=europe.pool.ntp.org
# North America
# NTP_SERVER=north-america.pool.ntp.org
# NTP_SERVER = time.google.com
# If NTP_SERVER is commented NTP_SERVER=time.izatcloud.net is used
Probably the best is to leave it at its default value (null → izcloud.net) hoping that izcloud would be globally reachable like google:
roberto]:~/Documents/Jolla$ host -t ANY time.izatcloud.net 9.9.9.9
Using domain server:
Name: 9.9.9.9
Address: 9.9.9.9#53
Aliases:
time.izatcloud.net is an alias for izattime.qcomgeo2.com.
izattime.qcomgeo2.com is an alias for izattime.xboxprod.izatcloud.net.
izattime.xboxprod.izatcloud.net has address 34.220.82.222
izattime.xboxprod.izatcloud.net has address 34.217.74.63
However, this is not the main point. Because, the proper solution is to make these value configurable by Settings:System → Location → Set services providers adding a specific button that bring to a new menu for those settings.
Instead, if you were refering to the dot-list: those are the available options.