There are no after-market hours in the forex market, except on the weekends.
Every forex market (Tokyo, London, New York, and every other market) is open and available for trading 24 hours per day, five days per week.
When we say that a particular market is "open" for 9 hours per day, from 8am (local time) until 5 pm (local time), we are simply saying that the majority of trading in that market occurs in that time period.
However, trading does not cease at 5 pm, and then resume at 8 am the next day. Instead, about 83% of each day's trading volume in each market (Tokyo, London, etc.) occurs in the 9 daytime hours betweeen 8 am and 5 pm, local time. And only about 17% of each day's volume occurs in the 15 overnight hours between 5 pm and 8 am the next day.
The best forex charts divide the trading week into 5 equal trading days, with "days" beginning and ending at 5 pm New York time (10 pm London time). The 5 trading days are:
Monday (trading day) --- begins at 5 pm Sunday, ends at 5 pm Monday
Tuesday (trading day) --- begins at 5 pm Monday, ends at 5 pm Tuesday
Wednesday (trading day) --- begins at 5 pm Tuesday, end at 5 pm Wednesday
Thursday (trading day) --- begins at 5 pm Wednesday, ends at 5 pm Thursday
Friday (trading day) --- begins at 5 pm Thursday, ends at 5 pm Friday
The 48-hour period between 5 pm Friday and 5 pm Sunday (during which time the retail forex market is closed) is ignored in these charts. So, the first candle on the Monday trading day (opening at 5 pm Sunday, New York time) follows immediately after the last candle on the Friday trading day (which closed at 5 pm Friday, New York time), without a space or gap.
There may be a gap in price between the Friday close and the Monday open, but there is no gap in time, according to this 5-trading-day method of charting.
Therefore, S/R lines, trendlines, moving averages, and all other studies and indicators are plotted as continuous lines (or curves), as if there were no weekend pause in the forex market. And this is true regardless of the time-frame on which you are plotting these studies.
I hope that clears things up for you.
Welcome to this forum, by the way !