hint: its basically a softlock if you use the key some times before you have to
114 days ago (+1)
that's not the solution.
SPOILERS (HINTS)
In case you need other hints for this combo here's some https://rot13.com/:
1. Jura lbh fjvgpu n '+' juvyr lbh ner ba gurer lbh pna tb bhg bs obhaqf naq jnaqre bire rirel bgure oybpx
2. sver fjvgpurf '+' bss (v qba'g erzrore vs lbh npghnyyl arrq vg sbe gur fbyhgvba)
3. Va guvf chmmyr lbh jvyy tb bhg bs obhaqf n ybg bs gvzrf, ohg bar gvzr lbh jvyy nyfb tb sebz bhg bs obhaqf gb vaobhaqf whfg gb or va gur evtug cbfvgvba gb tb ntnva bhg bs obhaqf jvgu nabgure '+' fjvgpu, orpnhfr lbh pna'g qb gung jvgubhg tbvat svefg bhg bs obhaqf.
FINAL BIG HINT
4. Gur jubyr guvat rkcynvarq va 3 unf gb qb jvgu gur '+' arne gur benatr beo fb gung lbh pna tb va gur hccre yrsg mbar naq gura va gur hccre evtug mbar (abgvpr ubj lbh pna'g tb gurer abeznyyl orpnhfr gur obkrf jbhyq unir nyernql snyyra oybpxvat lbhe jnl)
hope this was useful and sorry for bad english :)