When I did a three day week I worked M, Tue and W and took Thursdays and Fridays off. This gave me a long contiguous block, and meant that I was contactable on Mondays, when various start-the-week activities were scheduled.
The downside of the two day (Th and F) block when I wasn't around was that it was hard to contribute to projects that needed high levels of ad-hoc customer interaction. This actually meant I had to walk away from a couple of projects that were technically appealing, but I was at the point in my career (hence three-day week) where life-work balance was a higher priority, so this wasn't a hard decision.
Part of my decision on the timing was also influenced by discussion with women in the company who came back to a three day week after maternity leave. They pointed out the pros and cons of the various options and made it easier for me to pick the right option from the outset.
The downside of the two day (Th and F) block when I wasn't around was that it was hard to contribute to projects that needed high levels of ad-hoc customer interaction. This actually meant I had to walk away from a couple of projects that were technically appealing, but I was at the point in my career (hence three-day week) where life-work balance was a higher priority, so this wasn't a hard decision.
Part of my decision on the timing was also influenced by discussion with women in the company who came back to a three day week after maternity leave. They pointed out the pros and cons of the various options and made it easier for me to pick the right option from the outset.