My wall clock runs about 10 min utes fast per 24 hours. I has a pendulum with an ajustable screw at the bottom. Can I turn this screw to adjust the running time. If so, which way (shorten or lengthen)?

CLOCK REGULATION TIPS FOR THE ROTATING REGULATOR
These Regulations tips are useful for regulating the rotating regulator. This is to include most 400-day and 1000-day clocks.
The following information is copied from SCHATZ (tm) OWNER'S HANDBOOK.
Time Regulation Tip:
On the top of the pendulum is a disk on which numbers are engraved 1 - 16 and two arrows marked F - S. The small indicator hand will be pointing to a number on the disk at which the clock was regulated before leaving the factory. Should you find it necessary to regulate the clock, observe the number to which the indicator hand points. The distance between each number is equivalent to 1/2 minute in 24 hours + or -.
FRROM MY PERSONAL SHOP NOTES:
If your clock loses two minutes per day [24 hours] and the indicator hand points to number 8 on the disk - move the disk in the direction of the arrow marked F until the indicator hand will point to number 1.
NOTE:
Before attempting adjustments to the regulator disk, first lock the pendulums by using the lever located on the front of the base. By so doing, you will avoid damage to the delicate suspension wire while turning the regulating disk.
Keep A Regulation Record:
Keeping a short Record of regulation and maintenance on your clock will make it much easier for you to keep it well with in its optimum time-keeping ability. We have found that using the guideline below helps.
Date: +/- in min: How much adjust in Degrees +/-: Personal Notes:
We recommend logging only the times the clock was wound, and any time the clock is regulated or reset.
Times of regulation will include any time the clock has exceeded a 3 to 5 minute error.
Use only ONE form of time references for this, a QUARTZ clock that is known for keeping good time is recommended.
Over time you may find the clock needs only slight regulation; for example, if it has run for approximately 3 weeks and the error rate is under 3 minutes adjust regulator only slightly or simply RE-set.
TEMPERATURE and SEASONAL CHANGES
Temperature fluctuation can affect the time-keeping abilities of your clock.
Never allow direct sun light to come in contact with your clock. This will over heat the clock and it will not only affect the time-keeping qualities, but also dry out the oil and cause premature servicing requirements.
SPECIAL NOTES: REGULATION TENDENCIES
It is very difficult to look at the hands of an analog clock and still determine if the clock is running correctly, therefore I recommend allowing the time error rate on the clock to remain UN-touched until the error rate has exceeded + or - 3 to 5 minutes. This is because 1 minute is very difficult to observe and calculate effectively.
One little known fact about the Rotating Regulator: After the clock is restarted it can take up to 3 or 4 hours for the pendulum to settle down into regular beat rate. Example: If the pendulum is under rotated the clock will run fast and will take some time to bring it up to speed. If over rotated it will run slow. RECOMMENDATIONS ARE: Look at the actual clock time and reset it as closely as possible to real time after the clock has run for about 3 to 4 hours but don't disturb the pendulum. ONLY RESET THE CLOCK IF the actual clock time is off by 1 or 3 minutes.
If you must reset the clock every 3 to 4 weeks, and it is FOR EXAMPLE always slow, Slightly RE-Regulate the clock to compensate for this rate of error. Simply reset the clock several times just to make sure that no mistakes are made.
How to Calculate the Adjustment:
Calculating how much to turn the regulating nut on the rotating pendulum by using the following calculations.
Link to data base located at http://antiqueclock.clockstop.com/Regulate.html
　
Hope this tip helps.
r/David