As part of celebrations for the nation’s 46th birthday,
Singaporeans across the island and overseas are encouraged to take
part in the Pledge Moment on National Day in a reaffirmation of our
commitment and sense of belonging to Singapore.
To mark the start of the Pledge Moment, the Singapore Civil
Defence Force will sound a 20-second "chime" through the
island-wide Public Warning System (PWS) at about 8.10pm on 9 Aug
2011. The chime over the PWS will not be activated at the Float and
around the Marina Bay where National Day celebrations are
taking
place “live”.
Organisers of the National Day Parade 2011 hope that,
regardless of location,Singaporeans will recite the Pledge and sing
the National Anthem as one people after the chime has been
played.
http://www.scdf.gov.sg/content/scdf_internet/en/general/news/news_releases/2011/sounding_of_singaporecivildefenceforcechime.html