Work?

This morning I was asked to enter the bank transaction info for one of our clients into a spreadsheet. It's one month's worth, so about 3 pages of transactions, which if I was to work at it straight without sanity breaks would take about 15-20 minutes. Then my boss, relieved that I had something to do, told me I was just told to take my time with it. Then it was pointed out that, well, it does need to be done by the end of the week. So does this mean that I actually should be stretching 20 minutes of work across several days? Is that possible? Even for a pro time-waster like myself?

I'm taking this as a challenge against the Lord of Accounting. So far I've managed to make it last about an hour. Let's see where this goes!