how to shift in timetable?

i have this timetable how can i shift date time to the nearest date without affecting timetable?

[Peter Perkins]

Please give a specific short example of what you would start with and what you want to end up with.

Answer 1

[madhan ravi]

See lag()

[pooria mazaheri]

how can i lag this timetable to the nearest day?

Answer 2

[pooria mazaheri]

i have this timetable

how can i lag this timetable to the nearest day? (the present day is "01-Mar-2018" & the nearest day is "06-Mar-2018")

[Steven Lord]

What would you expect rows 4, 5, and 10 of the resulting lagged timetable to have as their Time information?

Midnight on March 2nd, March 7th, and March 7th respectively?

Midnight on March 2nd, March 6th (since 03:00 is before noon), and March 7th (since 13:36 is after noon)?

Or something else?