The recommended usage guidelines for Finasteride are to take a total of one tablet, once per day.
You can take the treatment at any time - day or night - though it is recommended to take at a similar time on consecutive days to achieve the optimal spacing between dosages.
Keep in mind that there aren’t any additional benefits from taking more than one tablet per day. In addition, you should not use both topical and oral Finasteride simultaneously. Doing so would not provide any benefits to your overall progress, but may increase your risk of side effects.
If you miss a day, simply skip it and resume by taking one tablet the next day - you should not take two tablets to make up for the missed dosage.