Read this article and answer this question In northern Scotland, the Jacobites were successful. They took Inverness, Gordon Castle, Aberdeen and further south, Dundee, although they were unable to capture Fort William. In Edinburgh Castle were arms for up to 10,000 men and £100,000 paid to Scotland when she entered the Union with England. Lord Drummond, with 80 Jacobites, tried under the cover of night to take the Castle, but the Governor of the Castle learnt of their plans and successfully defended it. By October, Mar's forces  had taken control of all Scotland above the Firth of Forth, apart from Stirling Castle. However, Mar was indecisive, and the capture of Perth and the move south by 2,000 men were probably decided by subordinates. Mar's indecisiveness gave the Hanoverian forces under the command of the Duke of Argyll time to increase their strength. Reinforcements were brought over from the Irish Garrison to boost Argyll. On 22 October Mar received his commission from James appointing him commander of the Jacobite army. The Jacobite army outnumbered Argyll's forces by three-to-one and Mar decided to march on Stirling Castle. On 13 November at Sheriffmuir, the two forces joined in battle. The fighting was indecisive but nearing the end of the battle the Jacobites numbered 4,000 men, compared to Argyll's 1,000. Mar's army began to close in on Argyll's forces, who were poorly protected, but Mar did not order them to advance, possibly believing that he had won the battle already . Mar then retreated to Perth. On the same day as the Battle of Sherrifmuir, Inverness surrendered to Hanoverian forces, and a smaller Jacobite force led by Mackintosh of Borlum was  defeated at Preston.
How many days after Mar received his commission from James did the two forces joined in battle?
22