This is a seasonal tendency that has existed since the 1920's. Stock prices tend to rise on the last 2 trading days of the month and first 3 days of the month. Does not necessarily rise every single day of those 5 days, but you might get a couple of good days.
Why do they rise? One reason is that pension and market fund managers receive distributions from employee paychecks at the end of the month and must invest those funds.
Another seasonal tendency is that stock prices tend to rise on the day before a holiday. Why? First, professional do not like to hold short positions over a holiday especially if it includes a weekend so they will buy back their position before the holiday. In addition, many professionals start the holiday early leaving only small investors who tend to buy instead of sell stock.