<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by JerryFF:
The other constraint is that your reservation, once booked, will only be held until 11:59 pm the day after you book it.</font>
Sort-of. It can be held until the day after you book it only if (a) you still meet the 14-days advance purchase and (b) the fare is still available that day (i.e. it does not have a buy-before restriction that is today's date.