till/to/until your dying day

to your dying day

for the rest of your life.

1967 George Mackay Brown A Calendar of Love This one always was and ever will be to his dying day a garrulous long-winded old man.

See also: dying

till/to/until your ˌdying ˈday

for as long as you live: I swear I won’t forgive her to my dying day!

See also: dying, till, until