Small helper functions that enable you to easily clone collections that contain a date in the name (e.g. 'logs_2014-02-01') from one MongoDB instance to another.

mongodb_cloneCollection_helpers.js

function getDateString (date) {
    year = date.getFullYear();
    month = ('0' + (date.getMonth()+1)).slice(-2);
    day = ('0' + date.getDate()).slice(-2);
    return year + "-" + month + "-" + day;
}

function dateIterator (colBaseName, startDate, dayCount) {
    var date = startDate
    var i = 0;
    var collectionNames = [];
    while (i < dayCount) {
        date.setDate(date.getDate()+1);
        collectionNames.push(colBaseName + "_" + getDateString(date));
        i++;
    }
    return collectionNames;
}