Help for timechart display

[ChhayaV]

hi

this is mt search

index=tm_idx host="server" "finished executing normally" | rex field=_raw "(?i)Process\s\"(?<Processname>\w+)" | rex field=_raw "elapsed\stime\s(?<myduration>\w.\w+)\sseconds" |eval pname=Processname+":"+"Process" |timechart span=1w sum(myduration) by Processname usenull="f"|sort _time

i am displaying processes and their duration by week.I have kept a drop-down list to select a month but when i select month e.g September it gives me chart showing data from 29 august happening same for other months also.

I want to start my chart time from 1st of every month.how can i do it ?
Here i have selected march but i can see february data also which i don't want to.

Thanks

[HiroshiSatoh]

(I'm sorry if wrong)
It is extracted from 1st if I set a time range.

[ChhayaV]

hi
i have given drop down for selecting month and setting date_month as month selected from drop down

[ChhayaV]

i have already posted my search in question and m not extracting month

[HiroshiSatoh]

Will you show the search sentence of the dashboard?Because I do not know a point extracting in a month.