The way I see to handle this is in three stages...

1. A Data-Entry routine to capture individual YEAR, MONTH, DAY, HOUR and MINUTE. You have the LCD screen, do you also have say three buttons available that we can assign to UP, DOWN and SET function?

2. CalculateLinearFromDate routine, to calculate Linear Days from the Date component (again a form of Julian Date - the inverse of my CalculateDateFromLinear routine.

3. A method of generating the 32-Bit number containing the Linear Seconds to feed the iButton.

Sure it would be easier to have all those other functions in PBP... but isn't it fun doing it this way? And it also proves that IT CAN BE DONE!

I recall going to dinner once with an old retired gentleman that used to be the Data Processing Manager/IT Director of the Rolls Royce company. He recalled, that when he joined the company as a young Systems Analyst, one of his first tasks was to find an unsed BIT in memory to act as a Flag for a new feature in their Payroll program... they ran a weekly payroll for over 2000 employees on a computer with 8kb core memory! We've got it easy!