i can tell you my pond will be dug in one day to, not alone . i dont consider it a "huge" task for a 1 to 3 thousand gallon pond.
You need to read his original pond post - he was proposing a pond that was 10 feet deep on one end. Way more than 1-3000 gallons. If I remember he eventually reduced it to 6 or 7 feet, but it was still a big dig. And the whole mystery was the big rush he was in to get it dug and done in one day.
Have you ever dug a pond @DutchMuch ?