A period expression indicates a span of time, or a reporting interval, or both. The full syntax is:
[INTERVAL] [BEGIN] [END]
The optional INTERVAL part may be any one of:
every day every week every monthly every quarter every year every N days # N is any integer every N weeks every N months every N quarters every N years daily weekly biweekly monthly bimonthly quarterly yearly
After the interval, a begin time, end time, both or neither may be specified. As for the begin time, it can be either of:
from <SPEC> since <SPEC>
The end time can be either of:
to <SPEC> until <SPEC>
Where SPEC can be any of:
2004 2004/10 2004/10/1 10/1 october oct this week # or day, month, quarter, year next week last week
The beginning and ending can be given at the same time, if it spans a single period. In that case, just use SPEC by itself. In that case, the period ‘oct’, for example, will cover all the days in october. The possible forms are:
<SPEC> in <SPEC>
Here are a few examples of period expressions:
monthly monthly in 2004 weekly from oct weekly from last month from sep to oct from 10/1 to 10/5 monthly until 2005 from apr until nov last oct weekly last august