What does Back to Saturday Sunday mean?

Back to Saturday Sunday meaning in Urban Dictionary

When you get very drunk Saturday and forget to publish that image, or got home at like 6 a.m on sunday and feel weird saying "Took dis final nite such enjoyable" after that just add a #BackToSaturdaySunday or #BTSS showing everyone what you performed your day prior to. By doing this you can nonetheless publish a selfie for your ' Selfiesunday ' without appearing like you changed your clothing to take a selfie.