What does the install before date mean on a Philips battery?

Philips HS1 series and FRx non-rechargeable lithium batteries (M5070A) are warranted for four (4) years, from the date of installation, (typical) four-year installed life, provided the battery is installed by the five-year shelf-life date stated on the battery.

For example, the M5070A battery shown below has an Install before date of 2020-10, considered a shelf-life date, meaning as long as the battery is installed prior to this date, the battery will be warranted for (4) years, typical four-year installed life.

• the Install before date listed on the battery is not an expiration date.

• It is recommended to write the date the battery is put into service on the back of the battery.