All of central Europe is in one time zone, so when traveling to Germany from any neighboring country the time will be the same. If you’re making a phone call from somewhere further away, though, it’s always good to know what time it is so that you won’t ring your friends out of their sleep.
Here is a list you can use to easily figure out what the time in Germany is:
United Kingdom: add 1 hour (for example 2PM your time is 3PM in Germany)
United States Eastern Time: add 6 hours (for example 2PM your time is 8PM in Germany)
United States Central Time: add 7 hours
United States Mountain Time: add 8 hours
United States Pacific Time: add 9 hours
Australia Western Time: subtract 7 hours (for example 10PM your time is 3PM in Germany)
Australia Central Time: subtract 8 and a half hours
Australia Eastern Time: subtract 9 hours
New Zealand Standard Time: subtract 11 hours
I also pulled this useful map off of Wikipedia if you are in a time zone I haven’t listed:
And also watch out for Daylight Saving Time! Not all countries adjust their clocks that way, so there might be an additional one-hour difference.