The challenge poll is normally open for four days, as is the case here (23:59, 4 March to 23:59, 8 March). The Iron-Clad Menace poll was open for five, but that's because I forgot the 31st of January existed. Why four days? Generally speaking, we receive the vast majority of responses are received in the first couple of days. The crude chart below shows the poll responses times for the Post-Cold War Large Surface Combatant challenge. You can see the drop-off in responses quite clearly, and such are curve is typical. There are, for example, already 30 responses to the Fifth Generation Fighter poll with over two and a half days before the deadline. Have you had much trouble responding within the four day period? Do you know others who are? We can consider extending the polling period if there are enough people have trouble.
OK I can see that you've done some analysis on this.
Well I missed the ironclad vote entirely and only noticed this poll yesterday (6th March). Note that 23:59, 4 March for you is 11:59am, 5 March for us in the UK, for the US much later in the day on the 5th.
But I get your point from the graph and its good to see more votes if we have over 30 already.