A plan has two limits: the data on it, and how long it lasts. Whichever runs out first ends the plan.
When the clock starts
Validity starts when the eSIM first connects to a network at your destination, not when you buy it and not when you install it. This is why you can buy well in advance and install at home without losing days.
What that means in practice
- Buy before you fly, install on your home Wi-Fi, and arrive with it ready.
- Do not activate it deliberately before you travel just to check it works. Installing is enough of a check.
- Once it connects, it runs continuously, including days you do not use it.
Days rather than dates
A plan measured in days runs from first connection, so a 7 day plan that connects on Monday afternoon runs to the following Monday afternoon.
Seeing your dates
The app shows how long your plan has left once it has started. Before it starts, it shows as not yet activated.
When validity runs out with data left
The remaining data goes with it. If you need more time rather than more data, buying a fresh plan is usually the right answer. See "What happens when your plan expires".