Does free will have any effect on time of death?

Is death time fixed or can it be changed? For example, by smoking do we shorten our life span? Or do we lengthen it by taking care of our health?

Death time is not related to human’s free will or precaution but to pre-destination.

Wherever and whenever Allah (swt) wills a person to die, He (swt) creates a reason to send that person there.

"It is He who has created you from clay, and then, has preordained (you) an appointed hour of death. There is also an appointed hour of death (hour of resurrection) in His sight; then you are (still) having doubt!" (Al-Anaam, 2)
“And Allah grants respite to none when his appointed time (death) comes. And Allah is All-Aware of what you do.” (Al-Munafiqun, 11)
““If Allah (swt) has willed a person die in anywhere, He (swt) creates a need (necessity) that is a reason for his going there.” (Tirmizi)

One day, the angel of death glared at a man near Hadrat Solomon. After he left the man asked Hadrat Solomon who he was.
Hadrat Solomon said:
“He is the angel of death.” The man said:
“He glared at me as if he wanted to take my soul. Order the mind to take me to India.” So that Hadrat Solomon did. He sent the man to India.
The next time the angel of death visited Solomon (as), Hadrat Solomon asked:
“Why did you glare at the man near me last time you were here?” And the angel answered:
“I was ordered to take his soul in India. I was puzzled when I saw him here with you. But when the time came I went to India. I found him there and took his soul.” (Ibn-i Abi Shayba, Musannaf)