These are the days most beloved to Allah for righteous deeds. Ibn Abbas reported that the Prophet (peace be upon him) said no good deeds are more beloved to Allah than those done in these ten days, so that even jihad is not superior except for one who goes out with his life and wealth and returns with neither. Allah swears by them, "By the dawn, and by the ten nights" (89:1-2), which the mufassirun explain as the ten of Dhul-Hijjah. Both pilgrims and non-pilgrims should fill them with takbir, dhikr, fasting, and charity.
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.