Bond tenting strategies do not care about your absolute age, they care about the number of years leading up to retirement and the number of years after retirement starts.

I’d like to model the % of my portfolio in bonds in terms of the above, i.e. * 5 years before retirement have 0% * At date of retirement have 40% bonds * 10 years after retirement have 0%

this would be helpful for simulating bond tents in terms of retirement milestone