1 Samuel 27:7

The number of days that David lived in the countryside of the Philistines [was] one year and four months.

1 Samuel 29:3

Then the commanders of [the] Philistines said, "What [are] these Hebrews [doing here]?" And Achish said to the commanders of [the] Philistines, "Is this not David, the servant of Saul, the king of Israel, who has been with me {for days and years}? I have not found anything [threatening] in him from the day of his desertion until this day!"

Treasury of Scripture Knowledge

Summary

And the time that David dwelt in the country of the Philistines was a full year and four months.

A full year

Bible References

A full year

1 Samuel 29:3
Then the commanders of [the] Philistines said, "What [are] these Hebrews [doing here]?" And Achish said to the commanders of [the] Philistines, "Is this not David, the servant of Saul, the king of Israel, who has been with me {for days and years}? I have not found anything [threatening] in him from the day of his desertion until this day!"