How to fix npm ERR! code CERT_NOT_YET_VALID npm ERR! errno CERT_NOT_YET_VALID npm ERR! Certificate is not yet valid in npm

Click the time/date display in the bottom-right corner of your taskbar. In the 'Date & time' settings window, ensure 'Set time automatically' toggle is enabled. This will sync your system to an internet time server.

For fastest results, restart your computer after enabling automatic time sync.

Ensure NTP (Network Time Protocol) is installed and running to keep your clock synchronized:

# Check current system time
date

# Install NTP if not present (Ubuntu/Debian)
sudo apt-get install ntp

# Restart NTP service
sudo service ntp restart

# For systems using systemd-timesyncd
sudo timedatectl status
sudo timedatectl set-ntp true

After updating, verify the time is correct with date command.

Older versions of Node.js and npm may have outdated or incomplete CA certificates. Upgrading ensures you have current certificate validation:

node --version
npm --version

npm install -g npm@latest

For Node.js, use nvm (Node Version Manager):

nvm install node
nvm use node

Once your clock is synchronized, retry your npm operation:

npm cache clean --force

npm install lodash --save-dev

npm install

If the error persists after confirming your system time is correct, the root cause may be elsewhere.

If you absolutely must proceed while troubleshooting the system clock, you can temporarily disable strict SSL validation. Warning: This reduces security:

export NODE_TLS_REJECT_UNAUTHORIZED=0
npm install

# Persistent (not recommended)
npm config set strict-ssl false

# Revert when done
npm config set strict-ssl true
unset NODE_TLS_REJECT_UNAUTHORIZED

Always re-enable SSL verification and fix the underlying clock issue.