I have this timer I wrote myself but its way too complicated and then when I need to get back to it to re-use it I already forgot how it works and always takes some time to understand. For sure there must be a simpler way to do it.

Here it is:

=IF(((E4/86400 DATE(1970,1,1)) TIME($K$9,0,0))<NOW(),"RENT", IF((TRUNC(((iferror(datedif(NOW(), E4/86400 DATE(1970,1,1), "d"),""))-TIME((24-(text(E4/86400 DATE(1970,1,1) - NOW() - int(E4/86400 DATE(1970,1,1) - NOW()) TIME($K$9,0,0), "HH"))),0,0))) - 365 * iferror(datedif(NOW(), E4/86400 DATE(1970,1,1), "y"),""))<(1),"",(TRUNC(((iferror(datedif(NOW(), E4/86400 DATE(1970,1,1), "d"),""))-TIME((24-(text(E4/86400 DATE(1970,1,1) - NOW() - int(E4/86400 DATE(1970,1,1) - NOW()) TIME($K$9,0,0), "HH"))),0,0))) - 365 * iferror(datedif(NOW(), E4/86400 DATE(1970,1,1), "y"),""))&"d ")&(TEXT((E4/86400 DATE(1970,1,1))-(now()-TIME($K$9,0,0)),"HH""h"" mm""m""")))

The "d" from days needs to disappear when ETA is less than 24h.

Is there a cleaner simpler way to do this?

My file: