I've done it every day this month. Some days it was just a couple sentences at the end of a very busy day, some days it was a couple hundred words. It is hard. There are some days when I want nothing more than to close the stupid document and never look at my own words again. But I force myself to type at least a couple words.
Sure, some days it feels like pulling teeth. But some days, even when it felt like the last thing I wanted was to write, I ended up getting on a roll and writing 2,000 words. If I had been easier on myself and let myself skip a day, those words might never have been written at all.
They aren't all perfect words. But they're words all the same, building the manuscript brick by brick.