It's important to note that this automatic-winding timepiece can nevertheless be manually wound should it run down. Simply take the crown in the first position flush to the case and turn it in a clockwise direction. After approximately 20 to 30 turns, the balance will begin beating and you'll see the advance of the constant second's hand at 9 o'clock. Alternately, you can check the case back to see if the balance is oscillating. Now at this point, you can replace the crown to its flush position should you have pulled it out for setting, put the watch on the wrist and it'll simply resume winding itself in the natural course of kinetic action on the wrist. However, should you wish to fully energize the power reserve of 50 hours simply continue turning the crown as you cannot accidentally overwind this automatic watch. The bridle-style mainspring will slip and relieve any excess tension.
Now, of course, there are the setting functions should you wish to correct the watch. It's important to note that the date should never be set between the hours of 8 p.m. and 4 a.m. as this is the period during which the automatic date-jumper mechanism is engaged. Attempting to quick set the date during that zone can damage the watch movement significantly. Always ensure that you're outside the realm of 8 p.m. to 4 a.m. when setting the time. This is significant because the El Primero sets a little bit differently than conventional calibers. The outermost position, which is usually the position used to set time on a conventional caliber, is on the El Primero used to advance the quick-set date. If you were to attempt to correct the time during that danger zone from 8 p.m. to 4 a.m., remember not to pull the crown all the way out because that will immediately engage the quick-set date corrector. Now in the second position, the watch does set its time. The second position allows you to advance the time in a clockwise direction. When you have the correct time set simply replace the crown to its flush position.
It's important to note with respect to chronograph usage that there's a particular sequence that mut be obeyed. Now the pusher at 2 o'clock starts and stops the chronograph. The pusher at 4 o'clock resets that chronograph. Now it should always be done in that fashion: start, stop, and reset. Attempting to reset while the chronograph is in motion can severely damage the mechanism. Always take care to stop it before you actuate it. Moreover, Zenith recommends against running the chronograph continuously as a sweep seconds hand. The largest register measures up to 12 hours. Zenith recommends that the watch not be run with the chronograph in action for more than 12 hours at a time.
Now water resistance is an important facet of watch maintenance care. Taking precautions in the presence of water can save you a lot of headaches and mechanical grief. It should be noted that this timepiece has a water-resistance rating of 50 meters, which is sufficient for surface activities, splashes and rain but no submergence, not snorkeling or scuba diving nor diving from boards or poolside that can create hydraulic shock against the pushers and crown. Moreover, water resistance is only as rated from the factory five ATM when the chronograph and the crown functions are not actuated. These may not be actuated underwater nor may they be actuated when there is water on the case as those actions can bypass the seals and introduce water to the interior of the watch.
Finally, it's important to note that water resistance is not a static feature of a timepiece. Over time as seals dry, as lubricants degrade, water resistance can ebb. Zenith recommends water testing with an authorized dealer of Zenith at least on an annual basis to ensure that the watch continues to meet the factory-rated hermeticity of five ATM.
It's also important to protect the watch in the presence of magnetism and from shock. Magnetism is significant because the timing capabilities of the watch are built around the metallic hairspring at the center of the balance.
Shock is also important as a traditional, fine mechanical caliber can be damaged by certain sports such as equestrian activities, motorcycling and mountain biking, firearms, marksmanship, tennis and golf. Avoid these activities while wearing your watch.
Finally, it's important to note with respect to service that the manufacturer Zenith recommends a full mechanical overhaul every three to five years by an authorized independent retail service center or a Zenith factory boutique as only these agencies have the trained personnel, specialized equipment and original Zenith replacement parts to maintain the integrity of your watch as an instrument and as an investment. Moreover, only these agencies can endow the parts and the work performed with an original Zenith factory service warranty.