Time in ASL lives on a line that runs through your body. Behind your shoulder is the past. Right in front of you is now. Out ahead is the future. Almost every time sign moves along that line, and once you feel it, you can read signs you have never seen before just by where they go.
The days of the week are the easy part, so let's start there.
Monday through Saturday
Six of the seven days are the first letter of the English word, circled in front of you with the palm facing the listener. Monday circles an M. Tuesday circles a T. Wednesday circles a W. Thursday is the exception within the pattern: a T that flicks to an H. Friday circles an F. Saturday circles an S.
Sunday and weekend
Sunday breaks the pattern. Two open hands, palms out, circle outward, a sign that some say comes from a congregation's hands raised in worship. Weekend is WEEK followed by END, a hand sliding across the palm and then chopping down off the edge.
Today, tomorrow, yesterday
Here is the timeline. Now drops two bent hands in front of you: right here. Today is NOW and DAY together, or just NOW signed twice. Tomorrow moves a thumb forward from the cheek, out into the future. Yesterday moves a thumb back from the cheek toward your shoulder, into the past.
The direction is the meaning. Forward is future, backward is past. That is why you can understand Next Week and Last Week the first time you see them: they are WEEK moving forward or backward.
Morning, afternoon, night
These show the sun. Morning brings a flat hand up from behind the other arm, like a sunrise. Afternoon holds the hand at a slight angle above the arm, the sun at the top of the sky. Night bends the hand down over the arm as the sun sets. GOOD plus any of these gives you good morning, good afternoon, good night.
Week, month, year
Week slides an index finger across the palm. Month runs an index finger down the other index finger. Year circles one fist around the other and lands on top, one planet orbiting another. Add a number handshape in place of the index finger to say two weeks or three months in one sign.
Asking what day it is
TODAY WHAT-DAY? with the eyebrows down. Or TODAY DAY WHAT? The answer is just the day sign. To say when something happens: MEETING WHEN? Answer: TUESDAY MORNING.
Practice
Every morning, sign the day and the time of day: TODAY TUESDAY, MORNING. Then one plan: TODAY I WORK. TOMORROW I REST. Before bed: YESTERDAY I ... and fill it in. That is thirty seconds a day and the whole timeline becomes automatic.
Next: Food and mealtime gives you the signs to fill those sentences with, and the Time Units category covers hours, minutes, and holidays.