Hi statalist!

I would like to make birth cohorts (5 years gap and above 25 years old adult).
I have age and birth year (variable age, byear) in my data.

My attempt was,
code:
gen cohort1=(age>=25 & age<30)
gen cohort2=(age>=30 & age<35)
gen cohort3=(age>=35 & age<40)
.
.
.
Is there any other way to make cohorts?
I will use this cohorts for difference in difference analysis.

Thank you for your help in advance.