OptionalextendExtends the start of the execution time range by a compact duration with integer
days, hours, minutes, and seconds in that order, such as 1h30m or 15m.
Zero duration disables extension. Unset or empty uses a fixed 15m at execution
time. Only the start moves; the end is unchanged. Has no effect on batch SQL
that does not use IN_TIMERANGE. Values must fit signed 64-bit microseconds.
Time-range configuration for a batch detection rule.