Here's a slogan cancel (on a postal card) for the First National Philatelic Week in the Philippines to be celebrated from November 16 to 22, 1952.
It was used in Manila from November 10 to 22.
Earlier, on October 10, President Elpidio Quirino signed Proclamation No. 342 "to draw the people's attention to the First Pan Asian Philatelic Exhibition" and to "declare the period from November 16 to 22, 1952, as the First National Philatelic Week in the Philippines".
This is not to be confused with Proclamation No. 622 signed on October 13, 1969 by President Ferdinand E. Marcos "declaring the last week of November every year as Philatelic Week."
The latter was observed from 1969 to the first half of the 1990s. It was superseded by the National Stamp Collecting Month celebrated every November.
(The first Philatelic Week issue, however, were overprints dated 1968 although these were issued on February 14, 1969. So, I'm really not sure if the observance goes back to 1968!)