A piano should be tuned 1-2 weeks after delivery.
A piano that has been moved and spent time in a truck may not be out of tune after it
is delivered. Pianos are tough and can withstand up to 20 tons of string tension and decades of heavy use, so moving usually has very little effect on the piano.
Steinway recommends 2 weeks and Bechstein 1 week after delivery. Remember the primary reason a piano goes out of tune is because of humidity changes.
New pianos will go out of tune sooner because the strings are new and still stretching,
this is why piano manufacturers recommend four tuning the first year.
A piano will always hold tune better when tuned by a skilled tuner, but stable temperature and relative humidity conditions will also increase the likelihood of good tuning stability.
Acoustic Piano or Digital Keyboard?
A keyboard may be inexpensive compared to the cost of a piano, and the size is hard to beat. And although a keyboard is able to stay in tune and produce a sound just like a piano, you will not hear the true and matchless tone that you hear from an acoustic piano.
Keyboards may work for students or anyone who is a beginner, but for the more serious musicians, teachers and connoisseurs I would recommend an acoustic piano. A piano may be an investment, but the value will stick unlike its digital imposter which will depreciate.
Many people may opt for a piano simply to honour the tradition. You can see the beauty in the structure, feel the power from a single stroke on the pearly white keys. You can open the lid and view the mechanics of the instrument and appreciate the intricate design.
Most importantly is the SOUND. You can create a sound of resonant amplification only produced by strings, felt hammers and wood. The pedals of a piano are used to create a whole palette of sound which is impossible to create in a digital instrument. The end result that you have created is truly unique and irreproducible.
It’s like wearing a diamond or settling for a crystal. The crystal looks like a diamond, it is pretty and sparkly and easy on the wallet, but it’s not a diamond.