This is a rather inexpensive world timer GMT watch most probably from the 1970s that needs some TLC. I love the shape of the case as well as the alternative red white black dial. Moreover, it has a nice rotating world time zones as well. I have been looking for an inexpensive world timer for a while.
For those who know, there was a time where there was a time difference between Singapore and Hong Kong. The change took effect on 1 January 1982, when Singapore moved half an hour forward, creating "Singapore Standard Time" (SST). SST is eight hours ahead of GMT and is synchronized with Hong Kong, Taiwan, Beijing, Manila and Perth. Thus, this watch must be from the 1960-70s.