(Fairly) long ago I mentioned, in the comment section, that some two-chapter days were coming (both as in 'two chapters published in a day' and also 'two chapters covering the same day'). We have reached that point. Friday will have chapters 55 and 56. The following Monday (the 19th) will have chapters 57 and 58. Other days will be single-chapter on the usual schedule, so these are nominally 'bonus chapters.' In both cases, I easily could have just made each day a (very) long chapter, but I feel like the split makes sense.