How to calculate the age of a contact in Bitrix24?

Question

Bitrix24

Update: figured it out, it was in quotation marks.
But now the question is how to display a negative value if the date of birth is greater than the current date? Thank you!

Good afternoon!
Tell me, please, where is the error:
You need to calculate the age in months. in the contact card
1) Created a custom field in the contact card to record age in it (field type integer)
2) Created bp by changing the variable {{=datediff({=System:Date}, {=Document:UF_CRM_5E8DD2AA4FF3B}, '% m')}}, where {=Document:UF_CRM_5E8DD2AA4FF3B} is the custom field date of birth of the child1
3) Created a variable with an integer field type.
4) By changing the document, I write (on behalf of the admin) the value of the variable in the corresponding field in the card
5) BP is triggered when creating and changing a contact card.
6) Nothing happens. The field where the age should be entered is empty ((((

Thank you very much in advance for your answer!

Answer 1

1) Check the quotes around %m. It must be quotation marks, not apostrophes.
2) Check the field code. As far as I know, there is no "{=Document:UF_CRM_5E8DD2AA4FF3B} in the cloud," in the last update there will be "{{Child's date of birth1}}"
3) You made an infinite loop. Changing any field leads to recalculation of the date and change of the age field.
Changing the "age" field is a change and bp fires again. You need to come up with a stopping mechanism. For example, add the technical field "Old date of birth of a child1" and check in the BP that if the value of "Date of birth of a child1" and "Old date of birth of a child1" are not the same, perform calculations. Otherwise, do not make any changes.
4) There is a special block - "report entry" where you can make the appropriate entries and understand how it displays the necessary information and what it really counts.