Help - Flist question about SPN filming schedule

[growyourwings]

I'm trying to remember, generally speaking, what the cycle of filming schedule is for SPN.   My memory is telling me it is something like...

• Begin filming in July
• Season airs in Sep/Oct
• Finish filming in March
• Season ends in May

I feel confident on the season airing/ending times.  And I'm pretty sure about when they stop filming because in the past it's generally coincided with one of the cons I regularly attend.   But my memory of when they start filming is sketchy.  I *think* it's July.  But perhaps it's June?  I'm pretty sure it's not later than July.  I know some of these dates have flexed a bit especially in more recent seasons when they added those extra two episodes to the seasons.  I'm looking for general timeframes.  Is my memory correct?

╚══════.♢.═╝