Setting the Timezone
By default docker containers will sync their clock with the system clock but the default timezone will be set to “UTC”. If we are using Date or Time in our application, we have to manually set the timezone for the container. One easy way to do so is by setting the environmental variable -e "TZ=Asia/Kolkata".
Syncing the clock
Sometimes, the container clock will deviate a little from the local system clock. OS X, linux and unix have ‘/etc/localtime’ file by default. We can mount this file as a read-only file inside the container. -v /etc/localtime:/etc/localtime:ro.