calendar alerts on iphone6s

[juniorhashim]

is it possible to customize the alert,
for example i would like to set the alert for 8 minutes before

 

[carolineM]

To a certain extent, but currently under IOS 11.2 you can choose from 5, 10, 15, 30 mins an hour, etc. up to a week.

 

[juniorhashim]

"to a certain extent?" -
i did not explain properly - i would like to specify my own time spans - i am assuming that i cannot - thanks for the assistance