Dear
I am new using time series analises in stata, so need some help.
I am try to use the ITSA command. first I used
tsset index dm
panel variable: index (unbalanced)
time variable: dm, 2010m1 to 2017m12, but with gaps
delta: 1 month

when I use this "itsa rate, single trperiod(2015m1) lag(1) posttrend figure" I have this error message: "trperiod() invalid -- invalid numlist"
when I try this "itsa rate, single trperiod(20151) lag(1) posttrend figure" I have this error message "Treatment periods not found in time variable: check trperiod()"
How can I solve this issue?
Thanks