[amibroker] Calculating No of Bars since Start of Previous Month

[chorlton_c_hardy]

Hello All,


I'm working in the Weekly timeframe and would like to calculate how many weekly 
bars have past since the START of the PREVIOUS MONTH.

I can easily find out how many bars have occured since the Start of the Current 
Month using:

BarsStartCurrentMth = BarsSince(Month()!=Ref(Month(),-1)) + 1 ;

However, I'm struggling to find how many bars have occured since the Start of 
the Previous Month. What makes this difficult for me is that not all Months 
contain 4 weeks.

Can anyone offer any help with this? 

Many Thanks in advance....