No, it's not better to sell your junk car at the end of the month. Timing only matters for traditional car sales, not for junk car sales. Dealerships chase monthly quotas, but junk car buyers and salvage yards worry more about your car's condition and scrap metal prices.
You're better off junking a vehicle before rust spreads, fluids start leaking, or the major components (engine, transmission, catalytic converter) start to have problems. Timing doesn't matter as much as the demands of the scrap market. Sell when scrap metal prices are high, sell before your vehicle deteriorates further, sell trucks and 4WD vehicles before the winter demand.
Check current scrap car prices to track market conditions.
