date

问题 Is it safe to directly compare ISO Date Strings like this: "2018-03-16T18:00:00.000z" > "2018-04-16T18:00:00.000z" // false It seems as long as leading zeros are used (proper ISO formatting) this comparison is safe and there is no need to convert the values to Date Objects. Am I overlooking something? 回答1: With the given format of a ISO 8601 time, 2018-03-16T18:00:00.000Z ^ you could use a direct string comparison, because the given time zone is a Coordinated Universal Time (UTC) If the time

问题 Is it safe to directly compare ISO Date Strings like this: "2018-03-16T18:00:00.000z" > "2018-04-16T18:00:00.000z" // false It seems as long as leading zeros are used (proper ISO formatting) this comparison is safe and there is no need to convert the values to Date Objects. Am I overlooking something? 回答1: With the given format of a ISO 8601 time, 2018-03-16T18:00:00.000Z ^ you could use a direct string comparison, because the given time zone is a Coordinated Universal Time (UTC) If the time

问题 Hi I need to remain only with the day of each date: df<-data.frame(x=c("2014-07-24 00:00:00", "2014-07-24 00:00:00", "2014-07-11", "2014-07-11" ,"2014-07-16" ,"2014-07-14")) as.Date(df$x,format="%Y-%m-%d" ) I tried this: df$dia<-as.Date(df$x, format="%d") But I get a full date and different from the orginal. I don't want to install another package to do this. How can I solve it? Thanks 回答1: Are you looking for format ? format(as.Date(df$x,format="%Y-%m-%d"), format = "%d") # [1] "24" "24" "11

问题 I am using following code to get the last 7 days: SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd "); Calendar cal = Calendar.getInstance(); Date date = cal.getTime(); String[] days = new String[6]; days[0] = sdf.format(date); for(int i = 1; i < 6; i++){ cal.add(Calendar.DAY_OF_MONTH, -1); date = cal.getTime(); days[i] = sdf.format(date); } for(String x: days){ System.out.println(x); } And this is giving the following output: 2016-04-14 2016-04-13 2016-04-12 2016-04-11 2016-04-10 2016

问题 I am using following code to get the last 7 days: SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd "); Calendar cal = Calendar.getInstance(); Date date = cal.getTime(); String[] days = new String[6]; days[0] = sdf.format(date); for(int i = 1; i < 6; i++){ cal.add(Calendar.DAY_OF_MONTH, -1); date = cal.getTime(); days[i] = sdf.format(date); } for(String x: days){ System.out.println(x); } And this is giving the following output: 2016-04-14 2016-04-13 2016-04-12 2016-04-11 2016-04-10 2016

问题 I'm storing messages from an amazon cloud and ordering them by their timestamp in a sorted map. I am parsing the timestamp from the cloud with the following code: Date timestamp = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss.SSS'Z'", Locale.ENGLISH).parse(time); and then I am storing in them in a sorted map with the key being the date. The issue is that the date only comes down to seconds precision. I can have several messages sent in 1 second, so I need them to be ordered with millisecond

问题 I'm storing messages from an amazon cloud and ordering them by their timestamp in a sorted map. I am parsing the timestamp from the cloud with the following code: Date timestamp = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss.SSS'Z'", Locale.ENGLISH).parse(time); and then I am storing in them in a sorted map with the key being the date. The issue is that the date only comes down to seconds precision. I can have several messages sent in 1 second, so I need them to be ordered with millisecond

问题 I'm storing messages from an amazon cloud and ordering them by their timestamp in a sorted map. I am parsing the timestamp from the cloud with the following code: Date timestamp = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss.SSS'Z'", Locale.ENGLISH).parse(time); and then I am storing in them in a sorted map with the key being the date. The issue is that the date only comes down to seconds precision. I can have several messages sent in 1 second, so I need them to be ordered with millisecond

问题 I have in my table a timestamps with created_at and updated_at $table->timestamps(); But I want to add another column that calculates the difference between created_at and updated_at in days Should I do that in SQL or in my controller? 回答1: You can do that from within your Eloquent model. Let's assume your model has the name User . You can create a computed field by defining an Accessor. class User extends Model { $dates = [ 'updated_at', 'created_at' ]; $appends = ['diffInDays']; public

问题 I have in my table a timestamps with created_at and updated_at $table->timestamps(); But I want to add another column that calculates the difference between created_at and updated_at in days Should I do that in SQL or in my controller? 回答1: You can do that from within your Eloquent model. Let's assume your model has the name User . You can create a computed field by defining an Accessor. class User extends Model { $dates = [ 'updated_at', 'created_at' ]; $appends = ['diffInDays']; public