Time FAQs

The Loop Phone Must be on Automatic Time

The Loop Phone is a Medical Device

The app relies on phone time when calculating active insulin. When you modify the time artificially to defeat screen time limits or to change the rules on a game, you run the risk of modifying that active insulin calculation.

• The Loop app detects if you modified the time

  • This is only possible when you disable Automatic Time in the phone settings
  • The app stops all automatic dosing of insulin other than your scheduled basal rates
  • The app will aggressively warn the user: Loop Warning about Time Change

• This detection is for your safety

• Some manual time changes can cause the app to crash and not reopen

This behavior is meant to prevent a situation where the user has a lot of insulin active but, because of the time change, the Loop app thinks they do not. The app could suggest a bolus or deliver increased insulin that could cause injury.

Not on Automatic Time

What can happen if you don't Force Automatic Time?

• Someone can change time manually
• This is not referring to time zone changes when you are traveling; those are handled for you when automatic time is enabled

If the time was changed manually and you pay attention to the warning:

• Sometimes you can recover by restoring time and deleting erroneous values, if any, from Apple Health
• Sometimes you have to delete the app and reinstall.

One worst-case scenario should be enough to convince you to Force Automatic Time:

• While a bolus was being delivered, a user manually adjusted the time to be in the past by changing time on the phone
• In this case, an exception was entered into the record that caused the app to crash (End Time for bolus was before Start Time)
• Their solution was to delete the app completely and reinstall
  • A deleted app means a new pod if that is the type of pump used
  • A deleted app means all settings and configurations have to be entered again

Force Automatic Time

You can configure the iPhone to only allow automatic time.

• Under iOS Settings, select Screen Time
• Scroll down to the Lock Screen Time Settings row
  • Enter a passcode

The ability to use anything other than automatic time is disabled as long as that iOS setting has a passcode.

• Adults can use this too in case they need a reminder not to change the time - you must first disable the passcode
• Parents can use this for children - but if they have family managed settings, they may need different instructions.

This does not affect automatic time zone changes, those are handled by the phone without need for interaction.

Test the Configuration

To test that Time & Date can no longer be modified, navigate to the following Settings:

• Settings > General > Date & Time

The option to modify "Set Automatically" should be disabled (greyed out), as seen in the screenshot below.

Automatic Time for Managed Phones

If you manage the Loop phone as part of a family account, forcing the phone to be on automatic time may take a few more steps.

After enabling Screen Time and creating a password, navigate to the following settings:

• Settings > Screen Time > Content & Privacy Restrictions > Location Services > System Services > Setting Time Zone

  • Disable the option for Setting Time Zone

Then return to the following settings:

• Settings > Screen Time > Content & Privacy Restrictions > Location Services
• Select the option "Don't Allow Changes".

Be sure to Test the Configuration.

Troubleshooting

If Time & Date can still be modified after making the above changes, try disabling Content and Privacy Restrictions or disabling Screen Time all together and then enabling it again. This might correct the problem. Test the Configuration again.

Note, when Screen Time is remotely administered through a Family Group from another person's iPhone, such as a parent, if the IOS version is not the same or similar to the child's phone, it can create unexpected behavior in Screen Time settings and can cause an inability to disable Time & Date modifications using Screen Time. Update both phones to be on the latest version of IOS and try again.

Remove Future Glucose

If you have future glucose from a manual time change or just entering something into Apple Health with the wrong timestamp:

• You MUST go into Apple Health and remove any glucose values in the future
• The Loop app detects the future glucose and stops looping
  • It might not be completely obvious why Loop stopped, but you will get a red loop within 15 minutes and Loop is not Looping notifications starting at 20 minutes
  • If you tap on the bolus icon, Loop informs you it detected invalid future glucose
  • If you tap on the glucose icon - it takes you to your CGM which probably has a very different number from that shown on the main Loop screen
• If you also use Nightscout and have the upload CGM readings enabled in Loop, those future glucose values will appear in Nightscout
  • To fix this problem (after you fix Apple Health), use the Admin Tools in Nightscout to remove future treatments and future entries

Loop Warning about Time Change

The Loop app is very aggressive at warning you if you make this mistake. you will get a notification - even when you are in a different app. The graphic below shows the alert when you next view the Loop app after turning off automatic time and changing the time. Even if you respond right away, you may have at least one glucose reading in the future when you see this alert. Please Remove Future Glucose.

The rest of this page is about changing time zones.

This is safe because the Loop app keeps track of records internally using UTC.

Time Zones, Daylight Savings Time, Summer Time

The Loop app operates across time zones and time changes. The phone that is running the Loop app will automatically update the time, but you choose when to modify the time zone for "pump time".

What Therapy Settings are set by "pump time"?

• Basal Rate Schedule
• CR and ISF Schedule
• Correction Range Schedule

Time Change comments:

• The Pump Settings screen is used to modify time zones
  • Tap on Pump Status Icon from the HUD
  • or Loop->Settings->Pump
• Travel
  • There is no urgency to update the pump time to match the wall-clocks when traveling
  • For short trips, many Loopers just leave the pump time alone
• Time Change (Daylight Savings Time or Summer Time)
  • Most people want to update their pump time immediately after the clocks change
• A Clock Icon is seen in the HUD Pump Status display when pump time differs from phone Time Zone

Medtronic Users

Do not use the Medtronic pump menus to change your pump's time when Looping.

iPhone

The Loop app will warn you if your phone does not have time configured to automatically update. The configuration is under iOS Settings -> General -> Time & Date.

Do not ever adjust the time manually on your Looping phone to "defeat" time-based rules for a game. Your phone with the Loop app is now a critical medical device - make sure anyone who uses your phone understands this.

Minimed Pump and CGM

The Minimed pump doesn't expose a universal clock, instead it exposes the components of a date (YMDHIS). It has no concept of political time zones, and just continues to increment its components on schedule. Therefore, the Loop app assumes that the pump's date, until changed, remains at a fixed offset from UTC.

That offset is stored by the Loop app the first time the pump ID is changed, and every time the pump's time is changed using the "Change Time Zone" command.

Dexcom CGM

No particular input is needed on your part for the Loop app to work with Dexcom CGM data. All times use UTC. However for Dexcom receiver users, at time changes you may want to manually change your receiver's time setting just so the time visually appears correct when you are viewing the screen.

Airports

RileyLinks, pumps and CGM have no problem going through any of the airport security systems. You can carry it with you in the airplane cabin and it can go through the x-ray scanner that your carry-on bags go through.

Airplane Mode

Nothing wrong with airplane mode, but many people forget about it at the time they travel. So, you can do this simple preparation step now:

Turn airplane mode on. Then make sure your Bluetooth is still slid “on”. If Bluetooth isn’t on, then go slide it on again. Now go ahead and turn airplane mode off again.

Why did we just do that? Because in older versions of iOS, airplane mode turned off Bluetooth the first time you ever use it. New iOS don't do that, but worth checking.

But, if you remember to turn Bluetooth back on while in airplane mode, two things happen (1) your CGM and the Loop app will work while in airplane and (2) airplane mode will “remember” the next time that you like Bluetooth left on in airplane mode and will not turn it off the next time you slide airplane mode on. So now you’ve just prevented yourself from forgetting to turn Bluetooth on the next time you fly and are in a hurry to meet your lovely seat mate and stow your luggage. You can safely follow cabin instructions and put phone in airplane mode without losing access to the Loop app or CGM.