According to the Hanafi school, it is permitted to shorten your prayers whilst travelling for a period of less than fifteen complete days and nights.

The reason why the number fifteen is understood to be the demarcator between travel and residency is due to the traditions (hadith) of Ibn `Abbas and Ibn `Umar (Allah Most High be well-pleased with them both) as related by Tahawi, Ibn Abi Shayba and others.
[Mawsili, al-Ikhtiyar li Ta`lil al-Mukhtar]

Please also see: The Basic Rulings of Travel and: The Definition of a Resident Person & Traveler

And Allah Most High alone knows best.

[Ustadh] Tabraze Azam

Checked & Approved by Shaykh Faraz Rabbani

Ustadh Tabraze Azam was born and raised in Ipswich, England, a quiet town close to the east coast of England. His journey for seeking sacred knowledge began when he privately memorized the entire Qur’an in his hometown at the age of 16. He also had his first experience in leading the tarawih (nightly-Ramadan) prayers at his local mosque. Year after year he would continue this unique return to reciting the entire Quran in one blessed month both in his homeland, the UK, and also in the blessed lands of Shaam, where he now lives, studies and teaches.