Microsoft Solitaire Collection

You need to complete a minimum of one daily challenge each day for a month, the level of the challenge completed does not affect the achievement, for example, completing an easy challenge each day will work.

As long as you complete a month's worth of challenges in date order sequence as per the achievement description it will unlock. You don't have to start on the first day of the month. This was true for myself and others on the recently obtained list. Completing the challenges in date order sequence is important, don't complete them in reverse order or out of sequence if you want it to unlock. I say this because I think completing challenges out of date sequence probably resets the day counter for the achievement.

For example you can start mid February and unlock the achievement mid March. I say this because I unlocked mine on the 12th, others unlocked it on the 27th and 1st etc. I think in my case the PC identified a sequence of daily challenges in place starting mid January. When I repeated a sequence of daily challenges starting on the 1st February the console added these on to the January sequence. So when I reached the 12th I had a long enough sequence of challenges to unlock it. I am not sure exactly how many days are counted as a month, I guess somewhere between 28 and 31.

Also the system clock does not have to be set to the present day to unlock, mine unlocked with it set on the 12th February, when the actual date was the 28th. You can also set the system clock to an earlier date (I think two months is the maximum) if you want the achievement quickly. Again just do them in date order sequence for the reason I mentioned above, repeating previously obtained daily challenges also works. Once I completed a daily challenge and set the calendar to the next day I logged out of Windows. I then logged back into Windows and completed the next challenge. I did this as a precaution to ensure that the Solitaire server recognised the new date for the next daily challenge.

If you don't want to do this legit by completing one Daily Challenge every day from the 1st day to the last day, here is a guide:

Change your date settings through Control Panel/Settings on your Windows 10/8 PC for the first day of one month which is already passed by now, like February 2017. Each time you complete a Daily Challenge for a day, exit out of the Daily Challenges menu then change the date from there, complete, then repeat until you complete one Daily Challenge for the last day of the month you are getting this achievement for.

I recommend you do this on a February (not in a leap year) since there are 28 days, which is much shorter by a few days compared to the 30 days/31 days in a month. If you have two devices (say a computer for the game and a phone for watching YouTube solitaire solutions), then you can watch Marcela Martinez and Zeming Jin's video solutions on how to complete the daily challenges if you are having some hard time trying to complete Daily Challenge(s).