Contact management, 2017
Many sites have different bonuses eg yahoo can import fb while fullcontact connects with twitter. I don't think its good to leave contacts on only one site , just incase one is down.  I also like having 'hard copy'. I do this every so often.


Mac Sierra
  EXPORT contacts->  all contacts -> edit -> select all (see count change) -> edit export-> vcard
 
  IMPORT to fullcontact (FC) site  ,
    settings -> import , selecting  the Mac-vcard from above
     link your social media contacts like twitter,  and  linkedin  if you wish
    EXPORT     fullcontact site:   backups-> select latest file
 
    IMPORT into yahoo, select contacts icon, select  import contact , add gmail and facebook if you wish
    EXPORT actions dropdown  select yahoo-csv , or mac vcf
   
    outlook IMPORT, select a file from above  and allow to select  a file  , then click upload , located  top left of popup box .  However  there is 2k number of contacts  limit and 5mb file size upload limit.
     EXPORT , outlook/hotmail : manage ->export
   
 IMPORT gmail , more-> import
 export gmail, select all the checkbox, more ->export , making sure to select ALL (third radio button)

 now import the gmail into Mac Sierra, file-> import

This process allowed me to save facebook, linkedin, google+ and twitter contacts and finally all in one file on my mac, where i can permanently store on backup drive

Yahoo Calendar: export calendar

If you wish to backup your calendar to your pc or import to another calendar system these are the steps.  It should be compatible with google calendar, and thunderbird:

at calendar.yahoo.com

on left side next to calendar click on the gear button

create calendar

enter name, then save

click on down arrow next to the calendar name, then select export