Clearly, this is a topic near and dear to all your hearts. And it has generated some really great discussion in the comments. Disgruntled Julie related that her PI asks her to take up the slack for some of the lab parents who have to leave early to pick up their kids (WTF!?!?). Silver Fox chimed in with what I would consider some very reasonable and rational expectations regarding the boundaries of working hours and other priorities (Silver Fox, can I come and work for you? Because I think it will be a cold day in hell before I find someone in my current field with this kind of sanity). Microbiologist XX left a comment that she thought was off-topic, but I really don't think it is:
I despise being told how many hours I should be in the lab or that I need to come in on the weekend. First of all, it isn't really fair and at the end of the day, it doesn't mean anything.
For example, when I am in the lab, I am busy from the time I walk in the door until the time I walk out. I multi-task my ass off. If I have a 30 min. incubation, then I start something new during that time. So, in one 8-10hr day, I get a shit-ton of stuff done. Sure it is super-stressful sometimes, but it is how I prefer to work. If I were to keep this pace up 6-7 days a week, I would go insane. In fact, if I were forced to come in on the weekends, I wouldn't get anymore done, I would probably just cram less into each day.
A different example. One of my co-workers chooses to read news stories and search the internet during all her incubations, etc. She gets way less done than I do in her day and she typically works at least one day every weekend.
So, it seems unfair to put a time expectation or a demand that you work almost every weekend when people work so differently. Personally, I would rather not dick around on the internet during the work day and not work on the weekend. The other student would rather work at a snails pace and put in more hours.
I think that if I have kids, I will be even more efficient during the day, since I know that my time is even more limited.
A lot of this work-life balance thing is observed, measured, and quantified in terms of hours in (or out) of the lab. Since general scientific success might be measured by other parameters (publication records?) for which data points are somewhat few and far between on the scale of day-to-day, it is only natural for our PIs to measure our work ethic and (perhaps inappropriately) our commitment to our project, our lab, our career, and science in general by other means (i.e., hours that our butts spend in the lab).
But as MXX very accurately points out, hours in do not always equal results out. I myself go through peaks of multi-task-like-a-maniac and troughs of faff-around-on-the-internet. And you know what I realized recently? The troughs correspond to when GrAdvisor is in town, and the peaks to when he is traveling. Why? At first glance it doesn't make any sense. He doesn't spend a lot of time in the lab so it's not like he's hovering over my shoulder or distracting me from my work. How is it that his presence in the office down the hall impedes my efficiency?
The reason is that regardless of how efficient I have been during the week, he expects to see me in on the weekends. As MXX pointed out, multi-tasking-like-a-mad-woman is not a sustainable level of activity/efficiency 6-7 days/week. So if I have to come in 6-7 days/week to pacify GrAdvisor, my efficiency takes a major hit. I get tired! And so I spend a lot of my hours in the lab faffing around on the internet when that time could be better spent working. But it doesn't stop there. When I am not being very efficient, I get depressed about my progress (because I am faffing around when I should be setting up more experiments), and general malaise sets in. I get a nasty case of Imposter Syndrome because things are not progressing as I know that they should and I beat myself up for not being a better scientist. It's kind of exhausting -- by 6pm I feel tired and go home even if just another hour could mean another experiment that runs overnight...but since I feel like my effort (or rather hours) applied do not yield results, what's the point? And then I lose motivation to set anything up because it's all going to fail anyway, right? This is not balance.
When GrAdvisor is out of town, I don't have to show up on the weekends to satisfy his accounting of my commitment to my job. As a result I feel free to take the weekends off, and knowing that I will do so motivates me to be much more efficient during the regular week so that I will not feel guilty about having two whole days away from the lab. Because of my somewhat bipolar approach, I find that I want to work longer hours/day when I am multi-tasking-like-a-mad-woman because I am getting SO MUCH DONE! This means that by Friday afternoon I feel that I have earned the weekend off...so I stay home (or go out) and enjoy the other things that I like besides science...and by the time Monday rolls around again I am excited to get back to the lab and see what else I can knock out this week. With this approach I feel that I am more productive in terms of data produced and experiments finished. This is how I know when my work and life are balanced.
In both cases I spend roughly equal amounts of time getting unequal amounts of work done. But my PI tends to measure face-time...did he see me come in on Saturday? If I was being really productive on Friday, why not continue to apply that efficiency on Saturday? If I wasn't all that productive on Friday, why am I not there picking up the slack on Saturday and Sunday?
It's a Catch-22...either way I lose my weekend.
It's a good thing he travels a lot. I couldn't sustain the 6-7 days/week of inefficiency if it happened all the time.
And like MXX, I kind of look forward to the day when I have children and therefore am not expected to do face-time 6-7 days/week...then I will have reason to maintain my super-efficient 5 days/week habit and it will be understood that this is allowed since I will "have a family" in a sense that is very different from the family I have right now.