What is the method for performing the shortened and combined prayers when traveling, and what are their prescribed times?

A traveler is permitted to combine the Dhuhr and Asr prayers, and the Maghrib and Isha prayers, while shortening the four-rak'ah prayers. This has regulations: He combines Dhuhr and Asr by performing them early (taqdim) if the sun has passed its zenith while he is dismounted and intends not to dismount before the sun turns yellow, or by delaying them (ta'khir) if he is in motion. He combines Maghrib and Isha by performing them early (taqdim) if the sun has set while he is dismounted and intends not to dismount until after one-third of the night, or by delaying them (ta'khir) if he is in motion. The proof for this is the hadith of Anas, which is agreed upon.