<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by VanMan:
So...I'm very happy with the outcome, BUT do we have to be very careful with a flight that leaves on the 31st March, but arrives on the 1st April, in future years?</font>
The date of your flight is according to the departure date, not arrival date. SIN UA was wrong - you did do the required 50K on/before March 31.