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