Various GGIR parameters expect us to provide a date or time format. R uses codes to define elements of a date or time format.
The table below shows the individual codes and their meaning:
| Code | Value |
|---|---|
"%d" |
Day of the month (decimal number) |
"%m" |
Month (decimal number) |
"%b" |
Month (abbreviated) |
"%B" |
Month (full name) |
"%y" |
Year (2 digit) |
"%Y" |
Year (4 digit) |
"%h" |
Hour |
"%H" |
Decimal hours (24 hour) |
"%I" |
Decimal hours (12 hour).0 |
"%M" |
Decimal minute |
"%S" |
Decimal second |
"%a" |
Abbreviated weekday |
"%A" |
Full weekday |
"%p" |
Locale-specific AM/PM |
"%z" |
Offset from GMT |
"%Z" |
Time zone (character) |
The table below shows examples of how to define time or data format using the above codes.
| Example time or date format | R code to describe this format |
|---|---|
"12-Mar-2025 15:05:02" |
"%d-%b-%Y %H:%M:%S" |
"12-Mar-25 15:05:02" |
"%d-%b-%y %H:%M:%S" |
"12-03-25 15:05:02" |
"%d-%m-%y %H:%M:%S" |
"2025/03/20 15:05:02" |
"%Y/%m/%d %H:%M:%S" |
"20/03/2025 15:05:02" |
"%d/%m/%Y %H:%M:%S" |
"20/03/2025 03:05:02 PM" |
"%d/%m/%Y %I:%M:%S %p" |
"Thu Mar 2025 03:11:06 PM" |
"%a %b %Y %I:%M:%S %p" |
"12-Mar-2025" |
"%d-%b-%Y" |
"2025/03/20" |
"%Y/%m/%d" |
For example we may set:
rmc.format.time = "%d/%m/%Y %H:%M:%S"when we see"20/03/2025 15:05:02"in a csv file with raw data.extEpochData_timeformat = "%d-%m-%Y %H:%M:%S"when we see"12-03-2025 15:05:02"in an externally derived epoch data file such as the Philips health band .xlsx data files.