The data set has dates in it but from looking at the result of str(newNgo) it doesn't seem that they are down as a date. Here's the results:
'data.frame': 4489 obs. of 24 variables:
$ Data.Source : Factor w/ 1 level "ngo": 1 1 1 1 1 1 1 1 1 1 ...
$ Incident.Reporting.Date: int 20051105 20080209 20090524 20111123 20111123 20111123 20111127 20111220 20111227 20120103 ...
$ Country : Factor w/ 2 levels "","Nepal": 2 2 2 2 2 2 2 2 2 2 ...
$ City...Town : Factor w/ 1966 levels "","-","Aalapot",..: 623 710 1937 1833 1913 1913 1192 659 1003 1698 ...
$ Address...Location : logi NA NA NA NA NA NA ...
$ Trafficking.Type : Factor w/ 5 levels "","Domestic Servitude",..: 1 1 1 1 1 1 1 1 1 1 ...
$ Trafficking.Sub.Type : Factor w/ 8 levels "","Child Marriage",..: 1 1 1 1 1 1 1 1 1 1 ...
$ Sources : logi NA NA NA NA NA NA ...
$ ID.. : Factor w/ 4380 levels "000be3119b46af67f9769a7d8f943d0d23a9cfc6",..: 2726 2725 2735 407 406 408 943 3618 1783 3616 ...
$ Location.Type : Factor w/ 2 levels "Destination",..: 2 2 2 2 2 2 2 2 2 2 ...
$ Incident.Start.Date : Factor w/ 1585 levels "01/01/2013","01/01/2015",..: 705 89 1227 790 790 790 814 909 926 11 ...
$ Incident.End.Date : Factor w/ 1585 levels "01/01/2013","01/01/2015",..: 705 89 1227 790 790 790 814 909 926 11 ...
$ Recruitment.Method : Factor w/ 538 levels "","13 bonded labourers rescued in W Delhi",..: 1 230 404 480 480 480 1 1 1 480 ...
$ Control.Method : Factor w/ 6 levels "","{"error" : "Phrase too long",\n "description" : "The phrase is too long. Maximum total length is 2,048 "| truncated,..: 1 1 1 1 1 1 1 1 1 1 ...
$ Transportation.Method : Factor w/ 7 levels "","Aeroplane",..: 1 1 1 1 1 1 1 1 1 1 ...
$ Trafficker.Nationality : Factor w/ 5 levels "","Asian","British",..: 1 1 1 1 1 1 1 1 1 1 ...
$ Trafficker.Gender : Factor w/ 4 levels "","Female","Male",..: 3 3 3 1 1 1 1 1 1 1 ...
$ Trafficker.Age : Factor w/ 70 levels "","0","1","118",..: 51 23 69 1 1 1 1 1 1 1 ...
$ Victim.Nationality : Factor w/ 25 levels "","Asian","Bangladesh",..: 15 15 15 15 15 15 15 15 15 15 ...
$ Victim.Gender : Factor w/ 4 levels "","Female","Male",..: 2 2 3 4 4 4 4 4 4 4 ...
$ Victim.Age : Factor w/ 67 levels "","0","10","11",..: 19 12 31 9 18 16 18 1 19 1 ...
$ InfoSource : Factor w/ 3 levels "Anonymous Tip",..: 3 3 3 3 3 3 3 3 3 3 ...
$ Title : logi NA NA NA NA NA NA ...
$ Geoname : logi NA NA NA NA NA NA ...