On portal, with Group By clause, the time is treated as local time Zone. However, without Group By clause, the timestamp will be considered UTC time and it will be converted back to local time zone in query. I am in PDT (UTC-7), this is what causes the 7 hour shift.
One solution to this is to (1) use UNIX_TIMESTAMP(t_stamp) instead of t_stamp in Time Column, and (2) remove the Where clause. (The data can still change with time zone though). See solution figure.
