Not sure I can help, I didn't have any issue going to the Daily after modifying my date/time. Are you sure you didn't set a time in the past ?
By the way it wasn't necessary for me to downgrade to revive the nook, I just had to remove the battery all night long and time was resetted. So it booted again
My previous post is now edited with a simpler command line. You just need to convert current time to unix format (numbers of seconds since 1970).