Routines (alphabetical) > Routines: C > CDF Routines > CDF_ENCODE_EPOCH

# CDF_ENCODE_EPOCH

The CDF_ENCODE_EPOCH function encodes a CDF_EPOCH variable into a string. Four different string formats are available. The default (EPOCH=0) is the standard CDF format, which may be parsed by the CDF_PARSED_EPOCH function or broken down with the CDF_EPOCH procedure.

## Examples

epoch_string = '04-Dec-1995 20:19:18.176'

epoch = CDF_PARSE_EPOCH(epoch_string)

HELP, epoch_string, epoch

; Create encode strings:

encode0 = CDF_ENCODE_EPOCH(epoch, EPOCH=0)

encode1 = CDF_ENCODE_EPOCH(epoch, EPOCH=1)

encode2 = CDF_ENCODE_EPOCH(epoch, EPOCH=2)

encode3 = CDF_ENCODE_EPOCH(epoch, EPOCH=3)

; Compare encoding formats:

HELP, encode0, encode1, encode2, encode3

#### IDL Output

EPOCH_STRING STRING = '04-Dec-1995 20:19:18.176'

EPOCH DOUBLE = 6.2985328e+13

ENCODE0 STRING = '04-Dec-1995 20:19:18.176'

ENCODE1 STRING = '19951204.8467381'

ENCODE2 STRING = '19951204201918'

ENCODE3 STRING = '1995-12-04T20:19:18.176Z'

## Syntax

Result = CDF_ENCODE_EPOCH(Epoch [, EPOCH={0 | 1 | 2 | 3}] )

## Return Value

Returns a string containing the encoded CDF_EPOCH variable.

## Arguments

### Epoch

The double-precision CDF_EPOCH value to be encoded. For more information about CDF_EPOCH values, see “Data Types” in the CDF User’s Guide.

## Keywords

### EPOCH

Set this keyword equal to one of the following integer values, specifying the epoch mode to use for output of the epoch date string:

Value | Date Format
0 | `DD-Mon-YYYY hh:mm:ss.ccc` (This is the default)
1 | `YYYYMMDD.ttttttt`
2 | `YYYYMMDDhhmmss`
3 | `YYYY-MM-DDThh:mm:ss.cccZ` (The characters `T` and `Z` are the CDF_EPOCH type 3 place holders)

where:

Date Element | Represents
`DD` | the day of the month (1-31)
`Mon` | the abbreviated month name: (`Jan`, `Feb`, `Mar`, `Apr`, `May`, `Jun`, `Jul`, `Aug`, `Sep`, `Oct`, `Nov`, or `Dec`)
`MM` | the month number (1-12)
`YYYY` | the year (A.D.)
`hh` | the hour (0-23)
`mm` | the minute (0-59)
`ss` | the second (0-59)
`ccc` | the millisecond (0-999)
`ttttttt` | the fraction of the day (e.g. 2500000 is 6 am).

## Version History

4.0.1b | Introduced

## See Also

CDF_EPOCH, CDF_PARSE_EPOCH