Fix panic with invalid system time

[ghost]

2/2 on timekeeping causing problems here :)

fuzzer doing good work

[codecov-commenter]

Codecov Report

Merging #469 (a45298c) into trunk (a14ea97) will increase coverage by 0.18%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##            trunk     #469      +/-   ##
==========================================
+ Coverage   66.82%   67.01%   +0.18%     
==========================================
  Files          35       35              
  Lines        2662     2671       +9     
==========================================
+ Hits         1779     1790      +11     
+ Misses        883      881       -2     

Impacted Files	Coverage Δ
src/error.rs	0.00% <ø> (ø)
src/features/impl_std.rs	77.55% <66.66%> (+1.68%)	⬆️
tests/std.rs	100.00% <100.00%> (ø)

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