Add Порт-Харкорт (Нігерія) to your list and use my-locations table to visually convert it's time to another timezone or city time.
Mouse over the colored hour-tiles and glance at the hours selected by the column.

Current time zone for Порт-Харкорт (Нігерія) is WAT, whose offset is GMT+1 from Greenwich Mean Time (GMT).

The IANA timezone identifier for Порт-Харкорт, Нігерія is "Africa/Lagos"

It currently does not observe Daylight Savings Time.