I was baffled by the line between metaphor and physical reality in this book. The premise is that certain formations --- of people's bodies, of spaceships, of... space stations? --- are powerful according to whichever calendrical standard one follows. This is never explained, and neither are the special area effects / technological effects of certain calendars. Under one calendar, a gun which amputates-at-a-distance works; under another calendar, it is useless slag. Under one calendar, standing in a particular formation protects from incoming artillery; under another, it does nothing. I was never exactly sure when the poetic descriptions of battles were literal and when figurative, since the physical reality was rarely described, but the ephemeral effects of calendars were often mentioned. It was never really clear why the calendar has such an effect, or why one couldn't just switch from calendar to calendar, as convenient for the particular technology at hand.
The book ended with a neat, tidy climactic battle, and set itself up to be the first of a series, with a fairly predictable protagonist-quest-outline of the subsequent books. I liked this book fine, but probably by bafflement and the formulaic one-person-takes-down-an-empire setup will combine to influence me away from reading subsequent installments.
This post's theme word is polonian (adj), "bounding in aphoristic expressions" or "a native or inhabitant of Poland." The polonian prose dissuaded me from further literary exploration.