In MongoDB, you can convert a string to a date by using the $dateFromString operator, which is available in version 3.6 and later. Here’s an example of how you can do it:
```
db.collection.aggregate([
{
$addFields: {
convertedDate: {
$toDate: “$dateString“
}
}
}
])
```
In this example, `dateString` is a field that contains the string you want to convert to a date and `convertedDate` is the name of the new field where the converted date will be stored. After running this command, each document in the specified collection will have a new field with the converted date.
Note that the `$toDate` operator uses a specific date string format, which is a string in the following format: `YYYY-MM-DDTHH:MM:SS.mmm+zz:zz`. If your date string is in a different format, you need to use the “$dateFromString” operator and specify the format of your date string.
`$dateFromString` operator example:
```
db.collection.aggregate([
{
$addFields: {
convertedDate: {
$dateFromString: {
dateString: “$dateString”,
format: “%Y-%m-%d” // change this to match the format of your date string
}
}
}
}
])
```
In this example, `%Y-%m-%d` is the format string where `%Y` is the placeholder for a four-digit year, `%m` is the placeholder for a two-digit month, and `%d` is the placeholder for a two-digit day. Change this to match the format of your date string.
