These instructions are from a Glashutte Senator Perpetual Calendar with the caliber 100-02. While these instructions may not apply to your exact Glashutte Original caliber, you can use them to get an idea how to best handle your watch. Remember, always use a proper tool to make adjustments, not a pen!
You can use the quickset to adjust the day, date, month independent of the time setting, however, do not attempt to make adjustments while the watch is between 7:00pm and 1:00am (as per the manual above, however, it is recommended to not set the time between 7pm and 3am to be safe). Why? Because this is the span of time in which the gearing is engaged in automatically advancing to the next day/date/month. The safe setting zone should be between 6:00am and 6:00pm.
There are some manufacturers that built the moonphase calculation into the perpetual calendar, so all you have to do is set the time. The GO system allows for quickset micro-adjustments of the moonphase independently of the time setting. As mentioned above, do not do this between the hours of 8:00pm and 2:00am.
Please not that these instructions are posted for information only and it is advised to take your perpetual calendar watch to an Authorized Glashutte dealer for help with setting it. Please also note that these instructions are borrowed from the Senator instruction manual.