After another shot-shy goalless draw at home to West Ham- a sixth of the season- the month starts badly and gets worse as the club's worst run since the late 1980s is offset by a crippling injury crisis and a manager fighting for his job at every turn.
There are calls for Van Gaal to go after the stalemate against the Hammers, but the mutterings reach a crescendo when United collapse in Wolfsburg to go out of the Champions League before the knockout stage.
Martial put United ahead early and own goal from the hosts makes it 2-2 and puts United in the box seat, but Naldo scores late to condemn the Reds to a third placed finish and the Europa League in 2016.
Van Gaal uses Nick Powell as a game-changer and is again guilty of muddled thinking as newly-promoted Bournemouth inflict a second consecutive loss on his side on the 12th despite Marouane Fellaini's equaliser as former United man Josh King hits the winner.
Van Gaal's position looks untenable as another promoted team (this time Alex Neil's Norwich) win at Old Trafford for the first time since 1989, coincidentally the last time United suffered such a poor run of form.
United again dominate possession but muster only two shots on target and are beaten for the third game in a row.
Tony Martial's second half strike reduces the deficit but fails to spark an uninspired United into life as the team are booed off by a mutinous and disbelieving home crowd.
Despite widespread reports of his sacking- amplified by Jose Mourinho's departure from Chelsea- Dutchman Van Gaal remains defiant amid silence from the club's hierarchy.
It appears things cannot get any worse but they do as United's season hits a new low with an atrocious showing at Britannia as Stoke easily triumph 2-0.
The Potters are pacy, powerful, clinical and creative- everything the Reds aren't, and it seems almost certain that Van Gaal will not be in charge for the final game of the month.
He survives again and although United end this tramautic month as they started it- with a 0-0 at home this time to Chelsea the performance is much improved and appears to buy time for the embattled boss.