Period defines reindex period.
time parameter understands this format:
xxxA[yyyB[zzzC]]where xxx, yyy, zzz are numbers (negative numbers are allowed), and A, B, C are interval specifier characters as follows:
s - second M - minute h - hour d - day m - month y - year
Note: The specifier characters are similar to format characters used by the
time value is put into single or double quotes,
spaces are allowed between xxx, A and
yyy, and so on.
If you specify only a number without any characters, it is assumed
time is given in seconds.
The default value is 7d (one week).