You don't need to "tend" to anything, you just need to pitch it and walk away. Many many of us leave our beers in primary for 3 to four weeks, then bottle it.
If you can't get to it for 6 weeks then I wouldn't brew til you got back, unless you were leaving in two weeks for a few months, then I would say rack to secondary after 10 or 14 days.
But if you think you have to rush it off the yeast or follow the silly 1-2-3 rule (which dones't factor in yeast lag) or the usually crappy instructions in your kit, you will find your beer will be better
if you leave it alone for a bit.
In Fact, Even John Palmer in How to brew mentions how it is good to wait a bit.
From How To Brew;
Leaving an ale beer in the primary fermentor for a total of 2-3 weeks (instead of just the one week most canned kits recommend), will provide time for the conditioning reactions and improve the beer. This extra time will also let more sediment settle out before bottling, resulting in a clearer beer and easier pouring. And, three weeks in the primary fermentor is usually not enough time for off-flavors to occur.
You shouldn't sit more that a few hours (like maybe 24 in a tight container using no-chill brewing methods) becasue anylonger will allow wild critters to take hold...you ideally need to pitch your yeast quickly to build up the numbers of "good" micro-organisms, to overwhelm any bad ones.