Fix error when write aligned tablet with null date

[HTHou]

As title

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 61.87%. Comparing base (8438467) to head (6d92a9a).
Report is 1 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #250      +/-   ##
===========================================
+ Coverage    61.67%   61.87%   +0.20%     
===========================================
  Files          491      491              
  Lines        32248    32250       +2     
  Branches      4226     4227       +1     
===========================================
+ Hits         19889    19955      +66     
+ Misses       11912    11848      -64     
  Partials       447      447              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.