Last modified time and Last modified by fields in Airtable

The last modified time field type and the LAST_MODIFIED_TIME()function reflect changes to editable fields made by a user. They do not include changes that occur automatically in computed fields—fields where the user doesn't directly edit record values—like formula fields and rollup fields.

Some computed fields can change values due to users making updates elsewhere. If the value of a computed field changes when a user makes a change, then you can use formula fields and formula function combinations to find out when changes that affected that computed field were last made.

NOTE

For example, suppose you're trying to determine when the value in a formula field changed most recently. In that case, you can often include the fields used in the original formula as parameters in the LAST_MODIFIED_TIME(). To determine the last modified time for a formula field using WORKDAY_DIFF({Assignment date}, {Due Date}, '2017-09-04, 2017-10-09, 2017-11-10'), you can create another formula field using LAST_MODIFIED_TIME({Assignment date}, {Due Date})—because changes to the WORKDAY_DIFF() formula field occur whenever modifications to the assignment date or due date field are made.

NOTE

The last modified time field type is a computed date field that automatically returns the most recent time and date a user updated a record in a non-computed field—a field that a user can edit directly.

1. Visit your Airtable homepage. 

2. Create or open your preferred base.

3. Add or edit a field.

4. Search for and select Last modified time. 

   1. From here, a window opens, allowing you to apply the field to “All editable fields” or “Specific fields.” For additional details, visit the “Customizing last modified times fields” section below.

5. Click Create field.

NOTE

The LAST_MODIFIED_TIME() function can also be used in formulas to return the time and date of the most recent modification made by a user in a non-computed field. Suppose you are primarily concerned with changes made to specific fields. In that case, you can include one or more field names in your LAST_MODIFIED_TIME() function, and it will only return the time and date of the most recent change made to any of the specified fields, e.g., LAST_MODIFIED_TIME(Status,{Due Date}).

NOTE

When customizing your last modified time field from the field customization menu, you can adjust which specific values are returned in the "Fields" tab and how the values are formatted in the "Formatting" tab.

By default, the last modified time field will show "All editable fields," showing the most recent time and date a user modified any non-computed field in the table.

1. Visit your Airtable homepage. 

2. Create or open your preferred base.

3. Add or edit a field.

4. Search for and select Last modified time. 

   1. From here, a window opens, allowing you to apply the field to “All editable fields” or “Specific fields.”

5. Toggle ON the “Specific fields” icon to show only the last time specific fields were modified.

6. Toggle ON one or more fields from the popup.

   1. After confirming any selected fields, the field customization menu will show your choices. You can edit your selections by clicking the "Change selected fields" button.

7. Click Use selected fields, then Save.

8. Click Create field.

NOTE

You can adjust the field values' formatting by clicking the "Formatting" tab, which allows you to pick your preferred date and time formats and toggle ON/OFF "Use the same time zone for all collaborators" and "Display time zone."

NOTE

The last modified by field displays which collaborator(s) made the most recent change to records in your base.

1. Visit your Airtable homepage. 

2. Create or open your preferred base.

3. Add or edit a field.

4. Search for and select Last modified by. 

   1. From here, a window opens, allowing you to apply the field to “All editable fields” or “Specific fields.” For additional details, visit the “Customizing last modified by fields” section below.

5. Click Create field.

1. Visit your Airtable homepage. 

2. Create or open your preferred base.

3. Add or edit a field.

4. Search for and select Last modified by. 

   1. From here, a window opens, allowing you to apply the field to “All editable fields” or “Specific fields.”

5. Select “Specific fields” to only show the last collaborator to edit any of the following selected fields.

6. Toggle ON one or more fields from the popup.

   1. After confirming any selected fields, the field customization menu will show your choices. You can edit your selections by clicking the "Change selected fields" button.

7. Click Use selected fields, then Save.

8. Click Create field.

The last modified by field reflects changes in fields where you can make edits. This means that fields computed by Airtable such as formula, created time, and rollup fields will be ignored if their values change.

If the computed field relies on a value you edit, you can set the last modified by field to watch the fields referenced by the computed field. For example, if you have a formula with {Quantity} * {Unit Price}, then the last modified field can be limited to just the Quantity field and the Unit Price field.

Records without last-modified times may appear for a few different reasons:

• When a new blank record with no user-created values is created, none of the fields will contain last modified times because no users have made any modifications.

• The last modified time tracking started in May 2019. Any records that in your base(s) before May 2019 will return blank values in a last modified time field or for LAST_MODIFIED_TIME().

  • As a result, any new modifications made to the records will overwrite the blank value with the date and time of the most recent modification.

If LAST_MODIFIED_TIME() returns a blank value, and you're using LAST_MODIFIED_TIME() in a formula function that requires a date value (e.g., DATETIME_FORMAT() or TIMESTR( the formula function will not evaluate properly, which can cause error messages.

By wrapping your function in an IF statement that checks for errors, you can account for errors caused by blank last modified time values. For example, instead of TIMESTR(LAST_MODIFIED_TIME()), try IF(ISERROR(TIMESTR(LAST_MODIFIED_TIME())),BLANK(), TIMESTR(LAST_MODIFIED_TIME())).

NOTE

Items added or removed from a linked record field will display the last modified record field user.

If the displayed name of an item in a linked record field is updated, the last modified field will not change because the record's update was made in a different table.

However, if you do want the details of who last changed the records in a linked record field, you can still do this by adding a field to the other table (the Order Line Items table in this example) and then adding a lookup field to the original table to pull in the collaborator name.

The value of last modified time will change if you add or remove a record from a linked record field, but it will not change if the fields associated with the linked record(s) have been changed. For example, changing the primary field of the linked record or any other fields that live in another table will not update the value of last modified time. This is because you have not changed which record you have linked to, even if its values in the other table have been modified.

If you would like to know when the value of a linked record field type has changed, you will need to create a new field in the linked table first—either a last modified time field, or a formula field using LAST_MODIFIED_TIME(). You can then use either a rollup with a MAX(values) or a lookup field to pull the last modified time for the linked record(s) into your table.

• No users have made modifications - When a new blank record is created that has no user-created values, none of the fields will have any collaborators listed in the last modified by field, because no users have yet made any modifications.

• The record predates the last modified time feature - Last modified by started tracking from when the feature was enabled. (June 2020 is when we officially launched this feature.) Any old records that were in your bases before last modified by was enabled will return blank values. Any new modifications made to the records will overwrite the blank value with the collaborator who makes the most recent change.

• The base has been copied from a template or other base - When you copy a template or one of your own bases, the values for last modified by and created by are removed for the new base as they are new records.

Any record created using your account information will show you as a collaborator. Suppose you have set up an integration using a personal access token, or authorized via OAuth. In that case, all records created from the integration will be associated with you. Additionally, the name of the personal access token or OAuth integration will be shown in the activity feed.

NOTE

When changes to a record(s) being watched by the last modified by field are made via an Airtable automation, the last modified by field shows "Automations" as the most recent collaborator to make changes.