Yesterday, Friday Oct. 23, the zman hadlokas neiros for zip code 11230 (where the siren is located) was:
5:45:48 (according to myzmanim.com)
5:47 (according to hebcal.com)
The siren sounded at 5:41 and then again at 5:48 (times verified on a Verizon cell phone).
The duration of the powered siren was 30 seconds (plus several additional seconds as the siren wound down).
Hope this helps.