diff --git a/userspace/libraries/LibC/time.cpp b/userspace/libraries/LibC/time.cpp
index 8dbbd0d7..a1ae89a9 100644
--- a/userspace/libraries/LibC/time.cpp
+++ b/userspace/libraries/LibC/time.cpp
@@ -1,6 +1,8 @@
-#include <BAN/Assert.h>
 #include <BAN/Debug.h>
+#include <BAN/Math.h>
 
+#include <ctype.h>
+#include <string.h>
 #include <sys/syscall.h>
 #include <time.h>
 #include <unistd.h>
@@ -107,6 +109,346 @@ struct tm* localtime(const time_t* timer)
 
 size_t strftime(char* __restrict s, size_t maxsize, const char* __restrict format, const struct tm* __restrict timeptr)
 {
-    dwarnln("strftime({}, {}, {}, {})", s, maxsize, format, timeptr);
-    ASSERT_NOT_REACHED();
+	size_t len = 0;
+
+	struct conversion_t
+	{
+		char flag = '\0';
+		int width = -1;
+		char modifier = '\0';
+	};
+
+	static constexpr const char* abbr_wday[] {
+		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+	};
+	static constexpr const char* full_wday[] {
+		"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
+	};
+
+	static constexpr const char* abbr_mon[] {
+		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+	};
+	static constexpr const char* full_mon[] {
+		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
+	};
+
+	const auto append_string =
+		[&](const char* string) -> bool
+		{
+			size_t string_len = strlen(string);
+			if (len + string_len >= maxsize)
+				return false;
+			strcpy(s + len, string);
+			len += string_len;
+			return true;
+		};
+
+	const auto append_string_from_list =
+		[&]<size_t LIST_SIZE>(int index, const char* const (&list)[LIST_SIZE]) -> bool
+		{
+			const char* string = "INVALID";
+			if (index >= 0 && index < (int)LIST_SIZE)
+				string = list[index];
+			return append_string(string);
+		};
+
+	const auto append_value =
+		[&](const char* format, int value) -> bool
+		{
+			int written = snprintf(s + len, maxsize - len, format, value);
+			if (len + written >= maxsize)
+				return false;
+			len += written;
+			return true;
+		};
+
+	while (*format && len < maxsize)
+	{
+		if (*format != '%')
+		{
+			s[len++] = *format++;
+			continue;
+		}
+
+		format++;
+
+		conversion_t conversion;
+		switch (*format)
+		{
+			case '+':
+			case '0':
+				conversion.flag = *format;
+				format++;
+				break;
+		}
+		if (isdigit(*format))
+		{
+			conversion.width = 0;
+			while (isdigit(*format))
+			{
+				conversion.width = (conversion.width * 10) + (*format + '0');
+				format++;
+			}
+		}
+		switch (*format)
+		{
+			case 'E':
+			case 'O':
+				dwarnln("TODO: strftime moodifiers");
+				conversion.modifier = *format;
+				format++;
+				break;
+		}
+
+		switch (*format)
+		{
+			case 'a':
+				if (!append_string_from_list(timeptr->tm_wday, abbr_wday))
+					return 0;
+				break;
+			case 'A':
+				if (!append_string_from_list(timeptr->tm_wday, full_wday))
+					return 0;
+				break;
+			case 'b':
+			case 'h':
+				if (!append_string_from_list(timeptr->tm_mon, abbr_mon))
+					return 0;
+				break;
+			case 'B':
+				if (!append_string_from_list(timeptr->tm_mon, full_mon))
+					return 0;
+				break;
+			case 'c':
+				if (size_t ret = strftime(s + len, maxsize - len, "%a %b %e %H:%M:%S %Y", timeptr))
+					len += ret;
+				else return 0;
+				break;
+			case 'C':
+			{
+				if (conversion.flag == '\0')
+					conversion.flag = ' ';
+				if (conversion.flag == '+' && conversion.width <= 2)
+					conversion.flag = '0';
+				if (conversion.width < 2)
+					conversion.width = 2;
+
+				char new_format[32];
+				sprintf(new_format, "%%%c%dd", conversion.flag, conversion.width);
+				if (!append_value(new_format, timeptr->tm_year % 100))
+					return 0;
+				break;
+			}
+			case 'd':
+				if (!append_value("%02d", timeptr->tm_mday))
+					return 0;
+				break;
+			case 'D':
+				if (size_t ret = strftime(s + len, maxsize - len, "%m/%d/%y", timeptr))
+					len += ret;
+				else return 0;
+				break;
+			case 'e':
+				if (!append_value("% 2d", timeptr->tm_mday))
+					return 0;
+				break;
+			case 'F':
+			{
+				if (conversion.flag == '\0')
+					conversion.flag = '+';
+				if (conversion.width == -1)
+					conversion.width = 10;
+				if (conversion.width < 6)
+					conversion.width = 6;
+
+				char new_format[32];
+				sprintf(new_format, "%%%c%dY-%%m-%%d", conversion.flag, conversion.width - 6);
+
+				if (size_t ret = strftime(s + len, maxsize - len, new_format, timeptr))
+					len += ret;
+				else return 0;
+				break;
+			}
+			case 'H':
+				if (!append_value("%02d", timeptr->tm_hour))
+					return 0;
+				break;
+			case 'I':
+				if (!append_value("%02d", ((timeptr->tm_hour + 11) % 12) + 1))
+					return 0;
+				break;
+			case 'j':
+				if (!append_value("%03d", timeptr->tm_yday + 1))
+					return 0;
+				break;
+			case 'm':
+				if (!append_value("%02d", timeptr->tm_mon + 1))
+					return 0;
+				break;
+			case 'M':
+				if (!append_value("%02d", timeptr->tm_min))
+					return 0;
+				break;
+			case 'n':
+				s[len++] = '\n';
+				break;
+			case 'p':
+				if (!append_string(timeptr->tm_hour < 12 ? "AM" : "PM"))
+					return 0;
+				break;
+			case 'r':
+				if (size_t ret = strftime(s + len, maxsize - len, "%I:%M:%S %p", timeptr))
+					len += ret;
+				else return 0;
+				break;
+			case 'R':
+				if (size_t ret = strftime(s + len, maxsize - len, "%H:%M", timeptr))
+					len += ret;
+				else return 0;
+				break;
+			case 'S':
+				if (!append_value("%02d", timeptr->tm_sec))
+					return 0;
+				break;
+			case 't':
+				s[len++] = '\t';
+				break;
+			case 'T':
+				if (size_t ret = strftime(s + len, maxsize - len, "%H:%M:%S", timeptr))
+					len += ret;
+				else return 0;
+				break;
+			case 'u':
+				if (!append_value("%d", ((timeptr->tm_wday + 6) % 7) + 1))
+					return 0;
+				break;
+			case 'U':
+				if (!append_value("%02d", (timeptr->tm_yday - timeptr->tm_wday + 7) / 7))
+					return 0;
+				break;
+			case 'g':
+			case 'G':
+			case 'V':
+			{
+				// Adapted from GNU libc implementation
+
+				constexpr auto is_leap_year =
+					[](int year) -> bool
+					{
+						if (year % 400 == 0)
+							return true;
+						if (year % 100 == 0)
+							return false;
+						if (year % 4 == 0)
+							return true;
+						return false;
+					};
+
+				constexpr auto iso_week_days =
+					[](int yday, int wday) -> int
+					{
+						return yday - (wday + 382) % 7 + 3;
+					};
+
+				int year = timeptr->tm_year + 1900;
+				int days = iso_week_days(timeptr->tm_yday, timeptr->tm_wday);
+
+				if (days < 0)
+				{
+					year--;
+					days = iso_week_days(timeptr->tm_yday + (365 + is_leap_year(year)), timeptr->tm_wday);
+				}
+				else
+				{
+					int d = iso_week_days(timeptr->tm_yday - (365 + is_leap_year(year)), timeptr->tm_wday);
+					if (d >= 0)
+					{
+						year++;
+						days = d;
+					}
+				}
+
+				switch (*format)
+				{
+					case 'g':
+						if (!append_value("%02d", ((year % 100) + 100) % 100))
+							return 0;
+						break;
+					case 'G':
+					{
+						if (conversion.flag == '\0')
+							conversion.flag = ' ';
+						if (conversion.flag == '+' && conversion.width <= 4)
+							conversion.flag = '0';
+						if (conversion.width == -1)
+							conversion.width = 0;
+
+						char new_format[32];
+						sprintf(new_format, "%%%c%dd", conversion.flag, conversion.width);
+						if (!append_value(new_format, year))
+							return 0;
+						break;
+					}
+					case 'V':
+						if (!append_value("%02d", days / 7 + 1))
+							return 0;
+						break;
+				}
+				break;
+			}
+			case 'w':
+				if (!append_value("%d", timeptr->tm_wday))
+					return 0;
+				break;
+			case 'W':
+				if (!append_value("%02d", (timeptr->tm_yday - (timeptr->tm_wday - 1 + 7) % 7 + 7) / 7))
+					return 0;
+				break;
+			case 'x':
+				if (size_t ret = strftime(s + len, maxsize - len, "%m/%d/%y", timeptr))
+					len += ret;
+				else return 0;
+				break;
+			case 'X':
+				if (size_t ret = strftime(s + len, maxsize - len, "%H:%M:%S", timeptr))
+					len += ret;
+				else return 0;
+				break;
+			case 'y':
+				if (!append_value("%d", timeptr->tm_yday % 100))
+					return 0;
+				break;
+			case 'Y':
+			{
+				if (conversion.flag == '\0')
+					conversion.flag = ' ';
+				if (conversion.flag == '+' && conversion.width <= 4)
+					conversion.flag = '0';
+				if (conversion.width == -1)
+					conversion.width = 0;
+
+				char new_format[32];
+				sprintf(new_format, "%%%c%dd", conversion.flag, conversion.width);
+				if (!append_value(new_format, 1900 + timeptr->tm_year))
+					return 0;
+				break;
+			}
+			case 'z':
+				// FIXME: support timezones
+				break;
+			case 'Z':
+				// FIXME: support timezones
+				break;
+			case '%':
+				s[len++] = '%';
+				break;
+		}
+
+		format++;
+	}
+
+	if (*format != '\0')
+		return 0;
+	s[len++] = '\0';
+	return len;
 }