Processing time depends on your citizenship.
A visa may be issued on the same day except if you are a citizen from a country listed below:
15 days average processing time if you are a citizen from :
Afghanistan, Algeria, Bahrain, Bangladesh, Belarus, Burma, Burundi, Congo DRC, Egypt, Guinea, Indonesia, Iran, Iraq, Jordan, Kuwait, Lebanon, Libya, Mali, Mauritania, Morocco, Niger, Nigeria, North Korea, Oman, Pakistan, Palestinians, Philippines, Qatar, Rwanda, Saudi Arabia, Somalia, Sudan, Suriname, Syria, Tunisia, United Arab Emirates, Vietnam, Yemen, Zimbabwe, US Re-entry permit, US Refugee travel document.