This command mostly exists to ensure Homebrew is updated regardless of whether you invoke brew or not, which is the primary difference from the autoupdate mechanism built into brew, the latter requiring a user to explicitly run any of brew install, brew tap or brew upgrade.

Source: https://github.com/DomT4/homebrew-autoupdate

.zshrc

@@ -84,6 +84,8 @@ export PATH="/opt/homebrew/opt/sqlite/bin:$PATH"
 if [ "$TMUX" = "" ]; then exec tmux; fi
 clear && udot
 
+#brew update
+export HOMEBREW_AUTO_UPDATE_SECS="86400"
 
 PATH="/Users/eragos/perl5/bin${PATH:+:${PATH}}"; export PATH;
 PERL5LIB="/Users/eragos/perl5/lib/perl5${PERL5LIB:+:${PERL5LIB}}"; export PERL5LIB;